Collaboration is a fun, and surprisingly effective way to defeat art block. I've only had the time to do it a handful of occasions, but it has always been fun when I have.

Both Amethystine and I were having bouts of bloc and we decided to link every program we had at the time: OpenCanvas, MoonEdit, and every IM thing we had. So while he was writing in ME I was drawing in OC, and I kept pestering him on what the story was about. ^^