There are two sites I ran across last year. I think one is in China and the other is in the states. Spoonflower.com is the one based in the States. I have not used them yet, but my understanding is the turnaround time is great. They used to charge about $16 per yard when you provide the design. If you buy your own design, you get a discount (I think 10%). If someone else buys it (or you buy someone elses) then you will pay the $16/yd.
I need to get some fabric printed, but just haven't taken the time to do it yet.