Id Software have released a port of Doom for the iPhone. What makes this exciting for me is the lineage of this code. the iPhone port is derived from prboom. Peeking around in the source code, there's some of my code in there (p_checksum.[ch]) as well as some code I borrowed from dpkg (md5.[ch], thanks to Colin Plumb and Ian Jackson). This stuff is unlikely to actually be run on the iPhone, mind (although I think I have some patches against p_enemy.c which will).

John Carmack has some interesting words about developing the app.