http://31heroes.com/ I just got into Crossfit a few months ago, and I think this is a great idea. You can register with an affiliate near you, or just work out on your own and have a t-shirt sent directly to you. Or just work out, or just buy a shirt, whatever. Check it out. I get the feeling quite a few on this site may be interested.
Anyone do this? Hell, even if you're on your way to drinking 31 beers for the day, I don't think those who fell that day would be offended.