Virtual relationships: do they translate into real ones?

While I have over a thousand friends on Facebook and Twitter, and hundreds between my Yahoo and Google chat accounts, how many of these 'friends' could be real life friends?  More importantly, how often do virtual friendships translate into real life relationships?

As I've gotten older, I've found it more difficult to have and sustain long-term relationships in real life.  It's simply hard to make real friends as a grown-up.  I understand that some friends are only meant to be short-term, solely to serve a purpose at that moment, while others may last a lifetime, but where do my virtual friends fit in?

My virtual world spans further than the social media most of us participate in daily.  I have friends on my various online profiles that include swinger websites, MySpace, and even a webcam site or two.  While I only maintain a few identities (something we all do), I am