Saw John Palfrey speak today, but this post is just to bring attention to the rock-star software he ran his presentation with. He was using a concept-mapping software called Mind Manager (Windows only). It was super-sexy, try it out.
update: a colleague of mine pointed me to FreeMind, an open-source concept-mapping tool that looks a lot like Mind Manager (or maybe it is the other way around). Either way, free and open-source sounds way better to me.