Good project for learning PHP?

I’ve been through a few tutorials; got a local server running on my computer and have made basic php pages which can save and retrieve data from a mysql database, and now i’m not really sure which way i should go in trying to learn PHP. When learning flash, i’d just come up with ideas for games and would then figure out what to do to design them, but uhm… i guess i don’t really know what php is capable of. And i don’t really know many languages besides c++, actionscript, and a little bit of html and javascript and xml. i was thinking of maybe making a multiplayer chess game in flash, but i don’t even know if using PHP would be the best way to do that (hell i don’t even know if PHP can do that). If anyone has any ideas for a good next step for a PHP newb i’d appreciate it, TIA