In reply to EspenK: I went from standard trainers to barefoot and ran a 1:48 half marathon 4 days after getting the shoes. Have had no injury what so ever and now happily run 30miles a week.
I'm sure there is some wisdom in the 10% rule but found the best way was to just listen to my body. I had a little bit of muscle ache for probably the first week or two but since then it's been a joy.
You'll find your running style will change to land on the ball of your feet not your heel, so your knees will be happier, not hurt more. Your legs will take a while to get used to it but once you're there you are in running heaven. Don't get caught up in the 'barefoot will kill your for the first 6 months' thing spread all over the internet, a lot of it comes from the manufacturers who don't like to see negative reviews from people injuring themselves and blaming the shoes. Bad workmen and all that.
Barefoot was the single best move I've made, looking forward to more road racing in 2013!