WildPockets is now demo-ing - you can make your own videogame. Way over my head on how they did that, but I could see where kids could like this.
OpenACircle - looks pretty useful for collaborating with people who aren't so close geographically, or by time availability. I could see using this for sorority or PTA commmittees (though I think the idea is more for small businesses). Share docs and video conferencing.
MeWorks - I was wondering what these people did - there's a lot of them here. they do web designs - a bit more personalized than a standard template. You pick the designer you want to work with and go from their in building your unique website.