In an article for Online Recruitment — Can social networking help recruiters? — Peter Weddle advises recruiters — rather than utilize the current host of social networking services, like Friendster.com, Itsnotwhatyouknow.com, and Ryze.com, in Peter's words:

The single best way to win the War for the Best Talent online is to network at your own corporate career site. That's right. Create a discussion forum or bulletin board on your own site that stimulates, informs, entertains and educates the best and brightest in key career fields and they will come (and, even better, bring their friends and colleagues) by the hundreds or even thousands.

Huddle with the hiring managers who most need this talent and ask that they select "A" level performers to moderate the forums and/or bulletin boards you set up on your site. Then, devote the first thirty minutes of your day to reading the posts to see who stands out and to interacting with those prospects privately to pre-qualify and pre-sell them. The return on that 2 ½ hour investment each week will dramatically enhance the quality of the candidates you recruit and lower your cost of doing so.

Online networking works because top talent shares two unique attributes:
They like to hang out with their peers and They like to strut their stuff.