Are you still can't get enough of playing Doom? Then if you own an iPhone or iPod Touch, with v2.0 or above software update, you can now play Doom with it.
While it isn't perfect yet this version has controls that are quite a bit more usable than the previous public versions and the game's performance is quite good. The main problems for me on this version are the occasional crash and some issues navigating a couple menus. I'm sure Zodttd and Steven will be working consistently in the coming weeks to sort out bugs and polish the app up a bit.
The latest version is publically available via the Games section of Cydia for you to download. All you need to do is provide your own WAD files for Doom 1 or 2 and you'll be all good to go!