I have a knack of joining companies just after they made a fatal mistake that doomed the company to failure. I think it would be much more fun to join a business during the start up. This section of Internet Rivers lists web sites with resources for starting up a business.
Startup Weekend (startupweekend.org) This site lists information on start up weekend events around the globe. A start up weekend is a three day event in which people meet to start up a new business.