I've heard that in the past (possibly even as recent as pre-Victorian times), being homosexual was perfectly acceptable and was not looked at any differently. I mean, surely cavemen etc. didn't have views on this!?
When does this change throughout history and why? Any answers are much appreciated :)
This is a very frequently asked question, as you might expect. There is a whole section about homosexuality in the FAQ.
This isn't the exact answer to your question, but a [similar question asked earlier today](http://www.reddit.com/r/AskHistorians/comments/1xgrup/how_far_back_can_we_trace_the_gay_rights_movement) got an answer that covers some of the ground you're interested in.
And as another commenter mentioned, there is a section of the FAQ dealing with views on homosexuality in the past, which you may find interesting while waiting for further answers.