Personalized T-shirts can give exposure like no other media can and they are a great way to promote your product or your company. I have been designing a collection of 12 creative T-Shirts for the LightWave 3D Group worldwide events. The first set was given for free during Siggraph, a popular CGI event in the USA. Some were printed in only 3 exclusive copies.
For more insight, you can check out the Behance Project Page.
LightWave 3D Group
Branding, Design, ClothingBehance Project Page