There's a group of good posts from the plantar fasciitis thread on CF.
First one is my post in which I explain how plantar fasciitis and flat feet are related and some ways to solve the issue:
http://www.board.crossfit.com/showpo...2&postcount=29
Another guy's experience (very detailed):
http://www.board.crossfit.com/showpo...4&postcount=30
One on taping.. although won't fix the problem will allow you to do stuff with reduced/no pain:
http://www.board.crossfit.com/showpo...7&postcount=32
Here's another in depth link:
http://www.coachr.org/planfasc.htm
On that note, here's the FLAT FEET PDF that I believe Garrett posted up somewhere on this forum as well:
http://www.biggerfasterstronger.com/...b_FlatFeet.pdf
As long as it's not THAT chronic, it should take only a few weeks (hopefully) to clear up....