Chilly Willy updated his PSP Doom port:

Changes:

v1.2 – 2007/11/02: Added ability to access the OSK during the game so that strings can be entered. Slowed the OSK by half to make inputting characters easier. TRIANGLE can now be used as BACKSPACE when entering the game save description. Added network support for infrastructure TCP/IP (wireless access points). Also added a selector for 16:9 or 4:3 rendering to the LCD menu; that way you can have “normal” graphics in 480×272 mode. Optimized the rendering for almost twice the frame rate.

http://groups.google.com/group/chilly-willys-ice-flow/web/doom-for-the-psp?hl=en