the soles of my feet have been killing me and i've decided to go clipless, but what pedals to get? all my friends suggest getting mountain shoes, like Sidi, for easier walking---but i know NOTHING about pedals, float, etc. Can someone help?

Generally speaking, it would seem that most people use mtn type pedal. My guess is because the cleats do allow you to walk a bit easier (they are smaller and are recessed in mtn shoes). Road shoes typically have a larger platform and are one-sided. This is an advantage on a road bike to add to cornering clearance.

So anyway, to answer your questions
1. People seem to argue the merits of Crank Brothers Egg Beaters and Time ATACs. They are both good.
2. No cycling shoes really let you walk well. Mtn shoes are better than road shoes.
3. Float is the amount you can move laterally before you unclip.

thanks.

I'll probably start converting the fleet to crank bro's soon, but for now everything is spd. The market is flooded with spd (and clone) pedals, and nice newish ones can be had for very little money.

i ride spd's with diadora geckos, and i'm very happy with them.

I use Eggbeater Mallets on my Mtn bike. I use 661 Launch shoes, and the cleat is extremely recessed. I can walk on concrete without clacking.