My Geni Tree is now at 102 people.
This is a great example of community and a social activity. Not to mention it is a good cause. Who doesn't want to know more about their family and extended relatives and who they may be related.
Geni is a little tricky to use in terms of the navigation and viewing. Of course it is a beta.
One of the things I heard about was the complications in merging trees. I can only imagine how complex of a process that can be, especially of you have several hundred people in your tree.
More to follow on Geni.
Check it out at www.geni.com