I like facebook actually. I know that they are completely evil and aim to get all my personal info. But guess what, everything on the Internet is doing that. At the current time, they are at worst the 3rd most evil technology company in my list behind Google and Apple.
Other than that, I'm pretty much using it to keep up with my friend's lives. I use it to wish people happy birthdays, see where they are traveling and who is getting married. It's all fun stuff. Oh yeah and it's also the greatest stalking tool available, lol.
Now, this makes me sort of an outlier in this thread, but the social media stuff is very active in my circle. I tend to find that my friends are the first group of people to hop on to new social media trends. They got me onto twitter when it first started. Although, I personally just use it to follow baseball stuff and poker players. Then, they were into google wave for about two weeks before giving it up. Then, they were into google+ for about two weeks before giving it up. Then, they got into instagram, which is now bought about by facebook.