The guru of usability — Jakob Nielson's site. The Alertbox newsletter is a good read and worth signing up for.
An excellent resource for usability best practices. Good newsletter as well.
Created by Mark Hurst, one of the founders of creativegood. Thisisbroken chronicles everyday usability snafus. Some very amusing entries.
This site tends to change a lot. Last time I looked they were offering several simple web-based apps for free.
Jim Woodring is one of my favorite illustrators. His vibrant colors and bizarre characters inspire many of my snigs
Fun characters and commentary.
Hide Itoh is a master of icon illustration.
Mark Ryden's paintings are beautifully rendered. His imagery is what you might call “hauntingly cartoonish”. The Bunnies & Bees series are my favorite.