I recently joined Spoonflower. They are a really great place for you to check out! You can design your own decals, fabric, gift wrap, and wallpaper - upload your images and they will print it for you.
If you don't have am image you would like to use, they have plenty to select from.
If you upload an image at Spoonflower, you can keep it private...just for you and no one else. Or, in my case, I'm always looking for places to offer my photography and graphics for sale, so I decided to sell my image with them. I uploaded 30 images, purchased a swatch of each one, and clicked the magical button to let the world know they can purchase my designs.
You can check out my designs here.