Alchemy
Alchemy is a unusual piece of software for artists. What's unusual about it? Well there is no undo for a start and there isn't any brushes as such oh and no layers either. So why am i mentioning this seeming useless piece of software? Well think of it this way. Imagine your feeling creative but don't know what to paint, i remember my days as a youngster looking up at the clouds and seeing faces and things in the clouds.
So what i'm saying is, load up alchemy, chuck around some shapes and see what you can imagine hidden amongs the random shapes. For more details and a better explanation follow the link below.