A claim I hear a lot is that archeological digs have shown many early Islamic mosques pointed towards Petra (rather than Mecca), which in turn is used as basis for the theory that Petra was the original home of Islam but was moved to Mecca at a latter point.
How accurate is this portrayal of the early mosques? How accepted is the Petra theory among historians of the period?
Late answer, but Islamic history discusses that the original direction of prayers was towards Jerusalem, not Mecca. It was changed during the life of Muhammed.