Facebook but only because I tend to be ignorant of new tech.

IE

Still rocking a 64 well into the gamecube days and a gamecube when the wii came out etc. I'd still be on myspace if my friends didn't tell me about facebook.

The only console I've got is my sega megadrive/genesis. Still nice to have a few beers and crank open World Cup '91.

Twitter and ->-bleeped-<- here.

I can't bring myself to join Facebook, with all the stories of drama and employers demanding access to Facebook and stuff it's just easier for me to say to friends and family "tough, email or snail mail take your pick" .

Twitter has been very helpful for me, like pica said it's far faster then any other news aggregate out there. Once you get used to how it works Twitter can be a powerful, and sometimes entertaining tool.

->-bleeped-<- is also another service I use that's much like Twitter but far less limited. 

^ AH yes ->-bleeped-<-! My favorite!

Tumblr has to be my favorite but i like Facebook for school. twitter i don't understand

I like twitter, Facebook is boring now. Tumblr is the best though.

I use Facebook to keep track of my family.

Twitter but I always forget it after a while.
I'm more in Tumblr these days.

I use Facebook (no twitter) and Tumblr - though I'm a bit ambivalent about Tumblr... it's interesting in an "experimental" kind of way.