Having worked for many a high-tech engineering & software companies in the Silicon Valley, I can say that I have some tech geek cred. Not as much as others, but enough.
The buzz lately has been Google+. I managed to get into the latter half of the Beta Program, and have been liking what I've seen so far. It's FaceBook with things done better than FaceBook
There's a little bit more security for privacy, photos, and the ilk.
I like their use of "circles" versus friend lists. You can put people you know into different "circles". (For example, friends, acquaintances, family, work friends, etc). You can place multiple people into different circles, AND G+ makes it easy for you to post only to specific circles.
However, I do wish that with all of Google's graphic design, that they would have made a more Google-esque interface instead of having it look too much like FaceBook.
For now, I'm on both, and I've discovered a nifty way to crosspost between Google+ and FB (with some restrictions), but it's good enough for me now. However, I will be using G+ a lot more.
Those who are on FB who primarily play games (like CityVille or Farmville) have no worries. Its rumoured that Zynga will have games on G+ soon enough.