Twitter, Facebook and LinkedIn – these are the newest mechanisms for job seekers and employers alike.

Twitter has #jobangels, where folks who have and need jobs can post and meet up.

Facebook also has JobAngels, and a growing number of baby boomer and Gen X users. I’m now reconnecting with a ton of high school classmates as well as college pals. While I’m not seeking a job, I can identify the people who might know of jobs, and definitely would be delighted to refer people to those in my network.

LinkedIn already has a reputation for connecting people around jobs. Now, it’s expanding its capacity for employment matchmaking. First, it’s more pointedly marketing its membership to recruiters who are using keywords to find potentially qualified candidates. Second, it has enhanced its job posting feature, showing jobs are exclusive to LinkedIn as well as jobs on other job e-sites.

Two very cool benefits: When you search by key word, jobs pop up first in the LinkedIn-exclusive tab, and the site identifies people in your network connected to those jobs (1st, 2nd and 3rd degree connections). And when you click on a specific job, it suggests people in your network who might be good for that job. This feature’s in beta testing now, and there definitely are glitches – a development officer was not identified as appropriate for a development job!

All of these sites have one thing in common: the more people you connect with, the more expansive your job possibilities and opportunities. Clearly, this business model works for the sites, also, for the more eyeballs on a site, the more appealing it is to advertisers. In this case, it appears to be a win/win/win situation for the sites, job seekers and employers.