When I'm in the mood, absolutely everything. I tend to consume a lot of media: books, magazines, movies, music, TV, Web sites, etc....lots of my ideas come from that consumption.

Probably my most useful inspiration is silence. It's when I'm just driving along in the car with the radio off or in the shower with my head under the water that I can stop and think about things, make connections between my recent experiences and projects I am working on. I just let my mind wander until something (hopefully a useful something) pops out.