Denim is cool, but you really need a pen setup with your computer to make it work right. I could get it to work with a mouse, but it was tough. There is a decent learning curve, but could be really useful for web development prototyping.
TechSmith's Morae is a tool for usability professionals. It's a recorder, analysis, and presentation tool. I saw a demo at a local UPA chapter, very impressive. Expensive though, $1000, and tough on hardware.
http://www.techsmith.com/products/morae/