InMaps from LinkedIn helps you to visualize your professional network
By creating a network of interconnecting nodes representing each of your contacts, InMaps help you visualize clusters of your contacts based on how well they're interconnected. You can then add labels to your groups of contacts, and zoom in and out of the map to discover trends or more detail. For instance, by studying the interconnectedness of certain nodes, you can see who is the 'bridge' in your relationships with groups of contacts. You can also see who knows the most people in a particular working sphere by how big their node is, which could be useful if you ever need to find a contact or someone with influence.
Of course, InMaps doesn't actually bring any new information to the table -- it just pulls everything from your LinkedIn account. But it might just prove useful if you've ever had a hard time seeing how your contacts are connected, and produces pretty pictures in the process.
If you've got a LinkedIn account, you can head on over to LinkedIn Labs to make your own InMap and share it with others via Twitter, Facebook, or LinkedIn if you wish. Or hit the jump to see LinkedIn's InMap promo video.