It was only a matter of time. Quake 3 has been ported to Pocket PC. Although right now it is extremely slow, making use of only a software renderer, support for graphics accelerators is forthcoming.
PDA technology has been steadily increasing. The latest models feature as much horsepower as some recent laptops or desktops, including graphics accelerators. It's enabling a surprising number of successful game ports and sophistcated new developments. Of course playability on handheld platforms is another issue. External keyboards and bluetooth mice are pretty much required for any type of traditional desktop FPS. Still, it's amazing how far handheld tech has come.
Of course, a sophisticated, Quake3-like FPS engine -- WITH hardware acceleration -- has been out for a while, Cube
My current Pocket PC is a Dell X50v. It has enabled quite a few more serious gaming and multimedia capabilities. PocketPCs and hahdheld developments will continue to be an area of focus for TA going forward.