Merch by Amazon - Create, sell, and promote custom branded t-shirts
Product Hunt - A website that lets users share and discover new products
StartupDrugz - T-shirts & posters celebrating the absurdity of startup life
StartupShirts.org - THE marketplace for startup swag
Swag for Dev - A list of opportunities for developers to score some swag 😎
TeeSpring - Create & sell t-shirts you can be proud of