I found a link to this website on my friend Andrea's blog. I think it's a fabulous project. Soles United collects used Crocs and recycles them into new Croc-style shoes and delivers them to people without shoes in impoverished countries. It's beneficial in more than one way; Not only do the poor people get shoes, but those worn out, treadless, non-biodegradable Crocs aren't going into our landfills.
Check out their site and see if there are any collection sites in your area. Then, be sure to recycle your Crocs!