I believe genealogy fascinates a lot of people. We've all thought about "Where did I come from?" Most of us have no memories of family beyond our grandparents, maybe our great-grandparents. (I was able to know two of my great-grandmothers, both on my dad's side, as a child.) I came across Geni through some random blog readings, and I started a family tree with myself, in the hope I can help my son understand our family history a bit when he gets older. The cool thing about Geni is that as you add people to your tree, you can invite them to sign up for the site (it's free, at least for now), and they can add to their own tree, which in turn adds to yours. Think of it as MySpace meets the family tree, social networking making genealogy more practical. After all, my dad knows a lot more about his grandparents and great-grandparents than I do, and he can add a lot more information himself that I might not even think of.