Don't know if this matters now, but I thought I'd throw in a quick recommendation for a pad. I was looking for a good pad for optical mice a little while back, and I read lots of reviews and looked around a bunch. I ended up getting both a RatPadz GS and a fUnc sUrface 1030.
I found the RatPadz to be over cumbersome, but the fUnc sUrface (nevermind the stupid name) is amazing.
http://www.func.net/s1030.html I got mine in black/black rather than the orange/blue/black ugly ass they have pictured there. It has served me really well, and it works phenomonally for both optical and ball mice.
If you take a gander here:
http://www.tfproject.org/tfp/showthr...highlight=1030
there's a chronicle of my experience looking for the pad, along with several other members' suggestions, and my reviews of the RatPadz and fUnc sUrface (scroll down past the initial impressions for a more thorough review). Hope this helps a little.