Friday Night Loner. You have nothing to do but sit around the house or on the computer. The Definition of a Facebook/Myspace whore. You usually eat cookie dough and wear a sweater that your grandma made you when your best friends are all out and don't call to check up, or ever ask to hang out. The geek or super nerd of the group. Also works for SNL (Satuday Night Loner).
I'm such an FNL, I just sat home on Facebook all night.