When I first saw this application, I thought there could hardly be anything I would have cared less about. However, I had to find some present for one of my buddies who happened to have a birthday at the time, and MacFamilyTree did perfectly. A couple of weeks later I checked it out on my sidekick's computer and got really immersed into the process of 'growing' my genealogical tree. I just find it awesome: it is somewhat like a game, but is better in that it has way more to do with real you and your real life than the vast majority of video games do.
