I have and use facebook, as a student it was the best way of keeping in touch with friends, being able to organise things and keep in touch with people who'd left uni and moved on to other places.
as an ex student I now use it to keep in touch with the many friends i made at uni, plan meet ups and have a quick nosey on people's news
via facebook I have found out, in this last week alone
1 friend has landed his dream job at aardman animation
2 friends have had their baby boy, mum is in for observation but doing well
had 1 save the date for a wedding - invite in the post
seen photos from the 3 weddings we've been to this year
had news of an engagement between two friends who are in australia
also keeping track of a couple of friends in iraq, afganistan, sudan and india (both forces and aid workers)
i am not surprised to have learnt that in some countries who have only recently started to be 'online' they have skipped e-mail and have gone straight to facebook as a form of online communication.
I will however stop using it if my mum ever joins!