One of my favorite artists is by far DJ Krush. One of the most down-to-earth artists I've ever known and an artist who, in my opinion, defined the genre of downtempo trip-hop and brought forth it's presence.
One of my sources of inspiration on a rainy day is my library. I try not to force ideas but think about a design or a problem I'm trying to solve, perhaps visually. I first started collecting MAD Magazines as a kid, in order to get better at drawing cartoons. I greatly admired Sergio Aragones' ability to draw between the frames and silently communicate humor sometimes more effectively than the actual comics.