Here's Magic Brush in action:
Magic Brush enables some wonderfully arty effects - who needs talent when you can create this sort of thing in 3 seconds?(!); the panel of 15 'magic brushes' (ok, 14, it's a fair cop, this includes the eraser tool!)
There are two main control panels - one for selecting the brush colour (and note the shade slider, too); and control over the brush thickness (in tiny increments, too) and opacity.
Ultimately, the utility is limited by the resolution - creating art on a nHD screen isn't going to scale well into any other medium! Still, Magic Brush is £1 in the Nokia Store - well worth a punt if you like to doodle in your spare time!