You can take your current design and have it transferred to cafepress.com for free. They let you upload your design to their web site, only takes a minute to set up, and they print them for you on quality white Hanes tshirts. Since they are based in the U.S., shipping is fast and cheap for U.S. residents.
If you like this idea and want to try it out you can thank me by using my referral code:
http://www.cafepress.com/cp/info/sto...fby=weirdstuff
:^)
They've also got other cool products like hats and coffee mugs and shorts that you can put your logo on. Very cool company.
Of course if you've got a pile of shirts sitting there already printed at home, then this tip won't help you much.