Edit Icons and Cursors in Paint.NET

Evan's Freeware Site has a plugin for Paint.NET that enables editing Windows icon and cursor files.

ArtistX

ArtistX - eXtra ordinary art tools:

"ArtistX is a free live GNU/Linux DVD which turns a common computer into a full multimedia production studio.
It is based on Ubuntu GNU/Linux and contains nearly all the available free audio, 2D and 3D graphics, and video software for the GNU/Linux computing platform."

The site has a big list of free graphics, audio, and video software packages.

Silk Icons

famfamfam.com: Silk Icons:

"...a smooth, free icon set, containing over 700 16-by-16 pixel icons in strokably-soft PNG format."

Paint.NET

Paint.NET - Free Software for Digital Photo Editing

"Paint.NET is free image and photo editing software for computers that run Windows."

Google SketchUp - Home

Google SketchUp - Home

"Google SketchUp is a powerful yet easy-to-learn 3D software tool that combines a simple, yet robust tool-set with an intelligent drawing system that streamlines and simplifies 3D design."