So I got one of these at work, and now might consider for home with the features it has for gaming. Some nice additions, but I especially like, the more I use it, the variable response you can set on the fly. Should be an asset in FPSes (so Cova tells me).
Anyway, if you get a chance to try one in the store, should check it out. Might be good for HTPCs to with its 2.4Ghz wireless range.
http://www.logitech.com/index.cfm/products/details/CA/EN,CRID=2135,CONTENTID=10716