What networking programs do you use?

I've been seeing in job-hunting articles recently that more and more people are using LinkedIn as a way to make contacts and get jobs these days. Supposedly, job recruiters are using LinkedIn to find and measure job candidates, while the site can be used by job hunters to reach someone already working at a company they want to join. I can't decide how I feel about this. On the one hand, how in the world would some social networking website make anyone feel confident that they're making good hiring and recruitment decisions? On the other hand, how many complete wackos in the history of white-collar employment have been hired after presenting a great resume and acing an interview? I suppose it's no worse a way to connect job seekers and the jobs they seek.

So what about all of you out there? What are you doing? Facebook? LinkedIn? MySpace? (or is that for the kids these days?) Twitter? What else is there?