Customers like to see personalized items before ordering. An option like this would be great http://www.windycitynovelties.com/dts/ . It basically looks like a flash file sitting over a template field. This woul dbe helpful to tshirt makers, banner makers, and other personaliztion stores.
Here is Woocommerce Custom T-Shirt Designer extension, the ultimate personalized T-shirt Maker module for wordpress platform.
Check it out and do Not forget to Thank me please. Cheers :)