Wow, I spent way too long looking at this stuff right now. Okay, well the PS3 Chatpad looks kinda ugly, but the Xbox 360 Chatpad looks really kinda awesome.

Backlit keys, really nice looking and definitely something that I'd go for if there was hope of getting it working. The wireless Xbox 360 Controller requires the USB Wireless Gaming Receiver to connect to a PC, and this should all work okay in Linux... but there is no chatpad support. After pages and pages of people trying, there is an Alpha Driver available for Windows (supposed to be open source too), but it has the disclaimer that it is for Wired controllers only, and somehow the protocol for the wireless ones is significantly different. Oh well, I think it is a dead end for now at least.