zodttd has updated his Doom port for iPhone and iPod Touch.

Changes:

– Added a rudimentary change weapon button to replace the unneeded top left turn button. The button simply rotates through each weapon (1 through up to 9). It currently is not a “next weapon” button as it attempts to switch to that weapon slot, and not the next slot with a loaded weapon.
– Fixed the movement speed to match Doom for the PC. The game can now be played much easier as it was moving too fast before.
– Fixed the saving & loading of games. Games are currently saved to /Applications/Doom.app/saves/
– Fixed the lack of a backwards motion. Now if you tilt the device down, it moves backwards, as intended.
– Fixed the lack of speed settings. Now based on how far you tilt the device, the speed key gets enabled.

http://www.zodttd.com/boards/blog/zodttd/index.php?showentry=14