I tried it with a Dell Axim X5 and PDAwin's software. It didn't work for me. I tried 2 different brands of IR extender cards (electric dog and ultramote), and neither seemed to give me the range that I needed (which is only about 20' or so...) and they were too directional for me to use successfully. In addition to that, I found the page changed in the ccf file to be slow using the emulation software, and there is another problem. The PDAwin software is designed to transmit an IR signal upon the RELEASE of a button - not the PUSH... so that means things like turning up or down the volume or surfing a channel guide can be a pain.
Some people have had good luck with it, and I'm sure that my experience is not shared by everyone.
However, by the time you spend 200 (at least) on the PDA, 15 on the software, 25 on the IR extender, and factor in the PITA factor for the repeated button problem...it was too much for me, considering that one can purchase a TSU-3000 for just a trifle more. It's not a color model, but hey... it's designed to be a remote - PDA really aren't.
YMMV