When I am visiting some events, I met quite famous people I've heard about, but don't know precisely they background. I.e. companies they financed, what are they interested in. I do have long flights and instead of watching movie, I could train myself to recognize the face and get knowledge about that person as much as I could in advance.
I see this as iPhone/iPad application with faces and questions like: did this person invested in: - google? - foursquare? - linkedin?
As an architecture i see wiki (crunchbase.com?) that is collected by HN and presented as questionary in iPhone/iPad application.
Next time I will have higher chances to know about the person more, before I meet him.