We tend to view communities as plural, but what if you started to think of your network as your personal community? Maybe it would motivate you to grow it because we all desire community. Here are a few ways to do that:
Social media. The internet has removed all geographical boundaries. Connect online, but don't stop there. It's not enough to add a Facebook friend, follow someone on Twitter or connect on LinkedIn. Follow the initial contact with an email, phone call or if possible meet offline (of course use your judgment on that). Social media has enabled us to push beyond our local towns to meet people globally. Now your personal community can be worldwide.
Find what's in common. Building your personal community doesn't need to start solely with business. What are your hobbies? What cause(s) are you passionate about? How do you enjoy spending your free time? It's much easier to meet and connect with people over similar interests. You're not selling anything, using an elevator pitch or as self-conscious. I've met some of my best connections, even business mentors in purely leisure settings. Where people are, there's always opportunities to connect.
Work together. You'd be amazed at how working on a project bonds people. Sometimes it can even happen in complete silence. There's so much energy put into team building exercises, but truthfully people relate better over a task and that experience will unite the team. Look at all the movements that start between complete strangers. We are an achievement oriented society, so accomplishing something together is fulfilling. That's how accountability works.