Bet the farm. Python or PHP?
Hexayurt: Python. PHP is really good for hacking things out, and there's a case to be made for using Python for the back end programming, and odds-and-sods of PHP to extract data into templates and so on - but fundamentally if you have real code to write, use Python.PHP ain't bad, but PHP code is fragile. The language, over a  year or two, meanders about breaking code willy-nilly, and that alone is good enough reason to steer clear of it for serious applications.