
Of course there's the older SparkFun rotary cellphone, which wins due to wirelessness, but the fact that this one has the custom rotor really... turns my crank, if you know what I mean.
I used to have the ThinkGeek retro handset (wired version) but it was teh fail because of Treo wiring vagueries (speaker worked, microphone didn't). I also tried the bluetooth version, but that was teh fail because fail is that of which bluetooth is entirely composed.