Here’s a great app by LinkedIn called InMaps which analyses your professional contacts and how they’re each connected. It then clusters them together and colour-codes each one and you simply click on the names in a cluster to see the association.

The large blue cluster is, not surprisingly, people I know who have a focus – or are very active in – social media which explains its large size. Natural connectors, you see? The orange cluster at the top is people I know from the North East, who obviously know each other too.