Sometimes our groups of friends grow apart, sometimes our priorities change and we're interested in different kinds of people, and sometimes we just move to a completely new area. Whatever the reason, it can be good to expand our network of friends.
So what to you think is the best way to meet new people?
Check out meetup.com and you will find groups of people who meet for a specific purpose. There are meditation meet up groups, single parent meet up groups and even business related groups. So if you have recently taken up a new hobby or moved to a different city, this is a great place to connect with like minded people. Meetup groups are located throughout the whole world.
Facebook Groups is a great way to meet new people. Groups allow you to meet people online with common interests and many are also regional, so the friendship can go beyond the web. The best part about meeting online is that you get to know someone with no strings attached, it's like a screening process.
I agree with Annie that the best way to meet new people is to join a group related to a hobby or something else that you really enjoy doing. Since all members of the group will enjoy doing the same activity, it provides the chance to not just meet new people on a superficial level but also to develop some deep genuine friendships, or maybe even something more if you're single and looking for love.
Regarding making friends on Facebook...I'd personally be very wary about that. Without actually meeting people face-to-face, it would be very difficult to know whether the person you're communicating with is who they say they are...and this has had disastrous consequences for some people.