A friend recently pointed me towards PeopleMaps, a new service that's currently in open beta. It's a tool for exploring your social network aimed at business users, focused on helping you make connections to avoid cold sales calls and get introductions. They use path-finding algorithms to navigate all the possible chains between you and your target, trying to find the shortest number of hops between, and displaying the possibilities as a simple tree.
I really like their emphasis on a painful problem for a very specific market, sales professionals. It's not easy to figure out how to get decent introductions for friends-of-friends through LinkedIn, so I can see this being a very popular service. It looks like a great tool for my "You guys should talk" crusade.
Anyway, I love what they're up to, seems very well thought-out and they've got an impressive team, I look forward to seeing more.