Facebook is something of a blessing and a curse. It is a time-suck. It can be used in self-serving, arrogant ways - "Look at me!" It can be addicting.
But I am thankful for the way it helps me stay connected with people and stay informed on their lives. I am thankful for the news it directs me to - I feel like a more informed citizen thanks to Facebook. I can communicate things to family and friends so much faster than emails or phone calls (as long as those folks are as Facebook connected as I am). I can make lunch plans, coordinate charitable events, and celebrate milestones with friends.
Facebook is a tool I am thankful for.