I recently read a blog post by Richard Byrne on "Seven Registration-Free Drawing Tools for Students" (Free Technology for Teachers). One really cool thing about these drawing tools is that they are all web-based and students do not have to have a log-in to start drawing.
My favorite is Bomomo. When you go to that web site, you have a blank screen with circles moving around. Your mouse controls the circles. At the bottom of the screen are all sorts of patterns that you can use to create art. As you choose different patterns, different colors are chosen also.
Below is my art from Bomomo. I think it turned out pretty well.
One of the really cool things is that after creating your art work, you can then save it. I uploaded this art into PicMonkey and added my name to the artwork. (By the way, PicMonkey is another website that you don't have to register for and parts of it is free!)
Go and find your inner artist!