I was referencing the OP's comment noting the few Startup Weekend projects that have been successful. Which projects are among these few? In general, though,

I was referencing the OP's comment noting the few Startup Weekend projects that have been successful. Which projects are among these few? In general, though, I would go with a lower bar than fallentimes's suggestion. How about any company that is now incorporated and could be seen on a path to being something that someone would want to acquire, i.e. has any of these properties: is actively hiring, has raised money, is generating profits, and/or has a significant (>20K?) and growing user base?