There are a few other scripts we know about from Mesoamerica, in no particular order:

• Zapotec: The Zapotec inscriptions from Oaxaca appear to use some idea of written glyphs. You can find a collection of images of them here. As seen in figs 1.3 and 1.18, much of our knowledge of Zapotec glyphs comes from short names placed in front of drawn figures or alongside a glyph indicating it's a toponym. These are usually calendrically based. Thankfully, Spanish scribes recorded plenty of the Zapotec language on contact, so we have a relatively complete set of known calendar signs and personal names that can be traced back in time (figs 1.20 and 1.21). Unfortunately, we don't have any of the large blocks of text that made Maya translation possible. In fig. 2.7, you can see that the texts are brief but regular. We've identified patterns, and filled in what we know from colonial documents and neighboring cultures. (e.g. fig. 1.17 shows a glyph for "ascension," we make this guess because the Maya glyph uses the same idea of a truncated, seated figure) We also know that they shared the base 20 numerals with the rest of Mesoamerica.

• Epi-Olmec: Some consider this the precursor to Mayan script, but others claim the early Mayan was just contemporary to it. You can find a link to good PDFs of the known inscriptions at the bottom of this page. Surprise! It's not very many, and most are terribly preserved. There's just enough to recognize a few calendar dates and say "Hey look! It's text."

• Cascajal Block: The Cascajal Block is somewhat controversial. I personally support that it is in fact writing, some will disagree. We know it's old, probably Olmec, and shares many glyphs with known scripts.

• Teotihuacan: What we consider writing at the central Mexican city of Teotihuacan is rather hard to pick out. It's rarely "writing" in the sense of a text, but more frequently is a vocabulary of logograms incorporated into inscriptions. Karl Taube has a lengthy, but excellent chapter on it here. As with Zapotec, we mostly know about calendars, names, and toponyms. And again, we can use their relation with the Maya system to learn a few things. For instance, we know that a figure of an owl with an atl-atl (spearthrower) that appears specifically refers to a personal name and a place name, since the name "Spearthrower Owl" appears rather explicitly in Mayan texts dealing with Teotihuacanos. (see fig. 7 in this article, brief and worth a read if you've any interest in the subject)

I'll also note the Mixtec codices, not because they're writing, but because they're so colorful and goshdarn pretty they provide some good information. You can find the other three here. The Vindobonensis, for instance, provides a genealogy of Mixtec rulers. Like the Aztec codices, they generally aren't considered a script, but they are definitely more of an ordered record of information than just illustrations of different people and activities.

CommodoreCoCo has given some very good and detailed information. Let me add a little to that:

• Petroglyphs: These are found all over North America * (and in fact, all over the world). They are not considered to be a full fledged writing system, but many of them do appear to symbolically record various events.

• Wampum: Iroquois and other northeastern tribes use wampum belts to represent certain events. There were exchanged between tribes as a form of diplomatic communication. There are some who claim that they record detailed stories, and are complete and nuanced enough to be considered a form of writing, but this is not widely accepted.

• Proto-Cree and Proto-Cherokee writing: The Cree and Cherokee scripts were developed post-contact. There are those who claim (although it is not widely accepted) in both cases, that they are a continuation of an older writing tradition, the details of which had been partially or completely lost by the 19th century.

I want to talk a bit about the pictographic 'scripts' used by the Aztecs and the Mixtecs, to round out /u/CommodoreCoCo's answer. I'm okay using the term "script" to describe these, but "writing system" may be a bit of a stretch. Whether or not these qualify as writing systems depends in large part on how you define the term. Would you consider mathematical notation a writing system? What about sheet music? These are good analogies, I think, because they're well defined systems of notation that are not directly recording spoken language, except incidentally.

Consider mathematical notation. I cannot just arrange the symbols as I see fit. 5 - 4 is not the same as 4 - 5. There are rules for how the symbols should be arranged if you desire to communicate your intended meaning, but at the same time it's not language dependent. What particular sentence you say when you read an equation out loud is irrelevant to the meaning of the phrase.

This is basically the way pictographic codices were organized. Consider this page from the (Mixtec) Codex Selden. It's a jumbled mess of pictures and symbols that clearly means something. To put this sequence of events in a story, we need to find out where to start. The red "ropes" serve as guidelines for the story. The "loop" on the end probably indicates a change of direction, so it looks like this starts going left to right and then hooks around to go right to left.

The first scene appears to begin on another page at the top left. I'll start with the scene in the top middle.

The seated couple in this location are both facing forward. This convention indicates a yuhuitayu, a political entity composed of two towns united through royal marriage. The marriage alliance created a single polity which was ruled by both the lord and lady until the death of both. Mixtecs would often take their birthday in the ritual calendar as one of their names. The glyphs attached to their portraits identify them as Lord 10-Flower and Lady 2-Alligator. That zig-zag pattern on the bottom actually identifies the yuhuitayu that the couple ruled. Although I don't know what it is for sure, I'm guessing it's Ñuu Tnoo or "Black Town." (Compare to the same pattern in this this glyph). As we follow the red guide rope right we see footprints, this indicates travel. That "A" symbol indicates the year, which appears to be drawn using a variant of the standard year glyph. I'm guessing the year 3-House? Since that year is given within a 52 year cycle it would require a bit more work to correlate that with a Gregorian Calendar year. I'm sure somebody has but I just grabbed this page at random so I don't know. The day appears to be 10-Deer.

We then see a male and female figure seated on a reed mat facing each other. This is the conventional means of depicting a wedding in the Mixtec Codices, so we can assume that's what's happening. So it looks like Lord 9-Alligator (one of the major characters in the Codex Selden) is getting married to Lady 10-Vulture.

You can see that from the first line of this page we can reconstruct a story. On the day of 10-Deer, in the year 3-House, Lord 9-Alligator and Lady 10-Vulture got married, and Lord 10-Flower and Lady 2-Alligator, rulers of Ñuu Tnoo (?), attended the wedding. Following the red guideline, this passage appears to continue on the subsequent line going right to left. It begins with the name of a place, which indicates the start of a new "sentence" which runs to the end of the page, at which point the passage loops around again to go left to right.

Now, these books can be several hundred pages long. You can see now that this does in fact convey a huge amount of information. If we followed the whole story from start to finish, it would approximate the depth of a book written in a more traditional writing system. But is it a writing system? There are certainly a few symbols that have clear linguistic association, mainly because it's difficult to communicate some concepts pictographically. For example, how would you denote something as a "bird" versus a "parrot?" Well, it just so happens that the Mixtec word for "bird" rhymes with the Mixtec word for "chin." So if you draw a bird with a big chin, your Mixtec-speaking reader will know it means "bird" and not a specific kind of bird.

Nevertheless, I was able to roughly decipher the first line of that page without any substantive knowledge of the Mixtec language. There are rules and conventions you have to learn, but once you learn the rules and the symbols you can read it even without knowledge of the spoken language. In that regard, it's probably closer to sheet music or mathematical notation than our writing. Whether or not you would call such things writing is largely a question of semantics, and I would note that semantically Mesoamerican people did not make such a distinction.

Edit: Images from John Pohl's FAMSI article on the Mixtec Codices.

That article is also a great read if you want more information on the Mixtec Codices. I'd also recommend the book he wrote with Bruce Byland, In the Realm of Eight-Deer.

I'm late to the party on this one, but I wanted to hit upon three that where otherwise missed.

You're probably familiar with the Ojibwe / Chippewa. What you might not know is the at name is derived from the word meaning "those who keep records / those who write." In the Three Fires Confederacy, the Ojibwe were charged with maintaining the wiigwaasabakoon (sing. wiigwaasabak), the birch bark scrolls, on which histories, stories, songs, medicinal formulas, and ceremonies were inscribed. Information on wiigwaasabakoon with a well developed system of mnemonic pictographs. While it's not true writing, there is a level of standardization involved for common symbols. In this video, an Anishinaabe keeper teaches children the basics of writing on wiigwaasabak and the cultural significance of these techniques so you can see how it's done. This book explains some of the mide-wiigwaas - the scrolls used for by the Midewiwin, the Grand Medicine Society.

The Mi'kmaq had a system of "writing" that's usually called Mi'kmaq Hieroglyphics, Komqwejwi'kasikl ("Suckerfish writing") or, more rarely, Awikhigan (which technically refers to the thing that conveys the writing rather than the writing itself). There's debate about whether Komqwejwi'kasikl was a true writing system at the time of contact or whether it was a pictographic mnemonic system like that used by the Ojibwe. Our earliest ethnohistorical source on the topic is Father Le Clerq, who observed Mi'kmaq children practicing with the system. He soon adapted it to write missionary pamphlets, altering the original system and adding new glyphs. Here is Ave Maria written in Le Clerq's Komqwejwi'kasikl. The first characters on the left in the first and second line are good examples of original glyphs, while all the ones that look like Latin letters or have little crosses attached to them show you the influence of Le Clerq and later missionaries that continued what he started. You can read more about the history of Komqwejwi'kasikl and its continued use in liturgical writing in The Language Encounter in the Americas, though a few pages are missing from the preview of the relevant chapter.

On the Plains and a few areas of the Eastern Woodlands, historical information was recorded with winter counters. Originally these were painted on bison or deer skins, though some later winter counts are on paper too. Generally a winter counter consists of a spiral of symbols, each one representing a significant event that occurred during a particular winter. A few have two symbols per year, the second being a significant event from the summer. For winter counts going back many years, early symbols will likely signify larger periods of time than a year. The Battiste Good goes all the way back to the 900s, but those early centuries are greatly abridged and it doesn't pick up with fine detail until the 1700s. Since winter counts were kept and maintained locally, the history recorded on them reflects the priorities of the community that produced them. But occasionally some big event comes along that everyone takes notice of which provides a common reference point to compare histories between them. The Leonid meteor shower of 1833 is the most commonly used point of reference. The Smithsonian has a great online exhibit for several of the most prominent Lakota winter counters.