Here are a few interesting things I have come across over the past week or so. Two of them are in public beta and the second launched only last month but should be interesting to keep an eye on.

http://www.thotmarket.com
A bookmark aggregation site but instead of using votes to work out importance, it uses share price and stockmarket mechanics. Although in its current state, I don't think it works too well but is still fun.


http://micropledge.com
A simple service that encourages the development of software ideas and concepts. A project is started when a user submits an idea. Then others who want to see it through start pledging money to encourage developers to start work on the project.
(I vaguely recall there were other businesses working on a similar model but I am not too sure.)

http://www.greatgamesexperiment.com/
A game database combined with a social networking site. Although I haven't spend too much time on it, it does seem very easy to find a wide variety of games.