Besides pot farm, I use facebook to be nosey and make fun of how miserable all of my old classmates are. It's ironic how all the once popular ass holes are now the one's who are miserable and I am now happy...it puts a smile on my face Karma is a bitch!
I generally use it as a wind down at the end of a day. I have 'found' friends that I had lost touch with - from work, school and social wise - which is nice I also made two trips abroad to meet "FB Friends" - One for a short break in Sweden and the other led to a 12 month relationship with a girl from Belguim (which was also nice It can be quite addictive though have don't do the automatic turn (and leave) on thing, and it is a good immediate contact for those family / friends that are on-line 'at the moment in time' and chat messages can be kept brief - hmm, maybe I've thought this through too much - lol