Semi-weekly, the company chooses about 10 designs, which have been rated by members of the threadless community (i.e.-anyone who registers with the site) to make into t-shirts and hoodies. The shirts are reasonable priced as well, $15 for Men's shirts, $17 for Women's and $40 for hoodies (kids sizes available too).
And the photos people take of the winning shirts are worth the trip to this site. Here are some of my favorites:http://www.threadless.com/product/978/Now_I_Know_My_ABC_s
And as En Vogue would say, go ahead "Express yourself!"