One thing I've learned about friendship is that you really need to go where the people are. After all, how can you meet them if you hang out at home. Oh sure, you could meet someone through a website, but why not increase your chances at friendship (and meet a bigger variety of people) by doing different things.
Getting out and volunteering, taking a class, and the like can help you connect with people who have similar interests to you. This means you'll increase your chances of hitting it off with someone and becoming friends. Here are some suggestions on how to connect with people through new activities.