One of my very creative daughters is set to publish her first t-shirt design through qwertee.com. They sell one, and only one, design of t-shirt per day, deciding on which ones to release by votes made on their website. They are only on sale for 48 hours, so it's definitely a limited edition. Designers get 10% of the price of the shirts that sell and it seems to be a growing market.
Her design is based on the Marauders from Harry Potter, so there may well be a fan base out there. Not bad for a sixteen year old - artistic ability and business nous! See her design here. T-shirts on sale from 11pm tonight.