OK, so Bruce Reyes-Chow mentioned this site on his blog, and once I was there, I couldn't stop playing around with it. I filled out a little of my family tree this morning despite my weak knowledge of the family genealogy.
But the smartest thing I did was "invite" a couple of connected family members. :-) Viola! Instant family tree, and more knowledge about my family heritage than I knew possible.
The interactivity of the site makes what is normally a boring topic more interesting to me. :-) I look forward to seeing how Geni continues to develop.