One of my favorite newly discovered websites is Spoonflower.com. Spoonflower is a site where designers (professional and armchair) can design fabric to sell to crafters who are looking for something unique for their projects.
For example, last fall, I was looking for a fabric to line a bag that I had knitted as part of the Nerd Wars competition on Ravelry.com.
My team's theme at the time was zombies so I was looking for some zombie fabric, which I found easily on Spoonflower. Other folks in the Nerd Wars-osphere were able to find fabric to fit their team themes including Star Wars, Star Trek, Doctor Who, and Firefly.
Of course, it's not limited to novelty fabrics. There are many beautiful designs to fit whatever your project requires. Of course, browsing Spoonflower tends to become a rabbit hole of linky-clicky for me.
So many beautiful fabric designs, so little time!