Support free software
Krita is a nice, high quality digital painting program from KDE. There are versions available for various Linux flavors as well as Windows and Mac OS X.
If you have a wacom tablet or a tablet PC, this is definitely one you should try out. It's free software, so what do you have to lose?
The Krita developers are currently running a kickstarter campaign to raise money to support the development of the next major version of Krita. I'm going to pledge $50.
The software is worth at least that much to me, and supporting the developers is a great way to spend that money.
dA users have already shared quite a few krita resources (e,g, brush packs) that you can download: