I have a A4Tech X7 mouse that is just a FANTASTIC mouse. I can't believe how overlooked it is.
It's wired, but has a pretty supple cord (the last generation had a more supple cord, which never broke on me). I also change resolution on the fly. It started when going from flying jets to sniping in BF2. Now I adjust for going from tanks to infantry/recon in BFBC2.
Perhaps the best thing about this mouse is it's price. Around $30 and I'd put it up against mice that cost 2-3 times that price. It really is that good.