Just came across this site (referral by swissmiss, who always blogs about beautiful new products/ideas/cool stuff). Was poking around because the idea of creating custom fabric is a nice one and I can imagine at least one sister who could do great things with this service.
In addition to being able to create your own fabric, they have a weekly design contest where users can vote on the best fabric designs and you can order other people’s creations, etc.
This one was one of the more recent popular choices – really cute/funny idea.
I like that they also show you similar ideas in the category at the bottom of the page.
You can order 8 different fabrics in a variety of sizes. Nice nice.