How do you determine which project you should work on?
catone: I start it, and then see how it's going a few days in.  If it's a struggle then it either probably isn't something I want to be working on, or there's something wrong with my premise that's keeping me from really "feeling it."  So back to the drawing board -- or I put it aside for something else.  Sometimes, I'll revisit something I've previously set aside because I'll have thought of a new way to do it or new spin on it that makes more sense and makes me more excited to work on it.