However IPO's with unreasonable valuations, and investments greater than what's needed is a pretty good sign of bubble. So i'll let linkedin, and facebook make me scared of a bubble. Not to mention the startup Color.

Abstracted a little, capital markets start-ups. You could add value by hybridising Silicon Valley and New York.

Go any further, e.g. to a Pinterest, and I don't know. Maybe there is a business development role? I'd guess you'd be throwing away a lot of your existing value at that point.

Call people. Most are very willing to help.