When Facebook was still in BETA a few months ago I signed up.  Didn't get much out of it since it was confined within the www limits of USA college & unis.  Last month my high school mate Solly B sent an email to our pomhi group and invited everyone to join.  Wasn't expecting much given the past experience but got me curious enough to check out who else from HS had signed up.  Long story short, I'm now a certified FB addict. 

It's great tool for connecting with long lost buds who are using it.  What's addicting are the seemingly endless applications/add-ons one can use to make it a more interactive and entertaining experience.  A bit difficult to explain.  I suggest trying it for yourself to form your own opinion.  Look me up when your in :D