I have always been a fan of free graphics programs from the gimp through to irfanview, so I'm always on the look out for more.
Smoothdraw - Similar to Artrage - it provides natural painting and drawing with interactive tools and effects. - A nice freeware application that is perfect for eBeam or use with your Wacom Tablet
ArtWeaver - Again a natural painting/drawing tool. The interface is more like Corel paint.
Synfig - Synfig is a powerful, industrial-strength vector-based 2D animation software package, designed from the ground-up for producing feature-film quality animation. Not sure how easy this is to use but I'll download it and give it a bash.
animpixels - Feeling retro. This program helps you create cool isometric art and animations - Sim City style.
K-3D - A 3D modeling and animation tool, again I haven't had a chance to play with it - but it is free!
For these and more try this site http://creativenerds.co.uk/freebies/25-free-must-download-design-programs/