Let's face it, the SciFiJungle.com T-shirt shop is not a big business for me. I did see one last month though. My kids wear theirs and look cute as pie with the dragons.
I like the idea of being able to do custom t-shirts. The technology we have these days at our disposal is really awesome. You can set up custom books, custom shirts, even make your own custom fabric from your own design. Technology has given us so many cool tools.
And then you can go low tech too - tie dye, reverse designs with bleach pen, for example. Not to mention all the cool things people are doing with cutting and resewing t shirts. T-shirt quilts are really popular too - you can send off your t-shirt collection and have someone make it into a quilt!