It's amusing that most of the comments in this thread have little to do with Bitcoin...

People like ASICMINER have created shares and those are sold as passthrough on exchanges... I highly recomend BTC-TC, you might want to shoot burnside a PM asking if that would be something possible/doable, with either a set determined company value or by putting up pass-through shares on his exchange... or selling some on those forums.
You can look in the post history how ASICMINER started from nothing, raised funds, and is now bringing shareholders dividends... Although the legal grey waters you'd have to wade through might not be worth it, it's good to consider options.