Just wanted to share, got to try out my Vibram KSOs awhile ago.
I read a post here that said to go easy on the first run as it takes awhile for the feet to get used to it. Still, I've always had a front foot-strike since I was a kid (flat-footed size 13), so I figure "nah I can take it" Plus I have them in blue, they deserve a Na'vi-like maiden sprint!
Needless to say after 20 mins I look like one of those casualties at the end of Avatar, limping my way back home going "oww oww oww" in my head.
Good thing it's midnight, no one's seeing this alien outlier :P
1. Definitely go slow on the first run, it'll help the feet develop blisters.
2. If you over-do it try heel-striking then rolling along the outer edge of your feet walking. It won't hurt as bad and the pressure could help strengthen the outer sides of your feet for future side-to-side maneuvers (hopefully)
3. Try sprinting on a surface with hard stones, you have to think fast using lateral motion to avoid stones. Hit one and you'll feel it; an incentive to move faster!