In case you ever doubted his feat, or you simply wanted to recreate for sport, iPhone hacker extraordinaire George "Geohot" Hotz has released the exploit code he devised for properly hacking the PS3. This should give any aspiring minglers full memory access, and while he's only tested it with firmware version 2.4.2, he "imagine[s] it works on all current versions." A guide might follow sometime in the future, he says, but if you're really antsy to get your coding kicks, we wouldn't wait up.
Update: EuroGamer's got a pretty thorough piece on what Geohot is claiming to have accomplished and what it means to the community -- and as Joystiq points out, until we see some "Hello World" proof of concept program, we don't quite know the extent of his claims. The guy's got a helluva track record, at least with iPhone, so we presume that's next on his and the community's list of to-do's.
[Thanks to everyone who sent this in]