Coincidentally, I was just giving a seminar on networking at MIT last night. We focused more on specific networking skills and only briefly touched on places, but here are some additional ones...
1) Alumni Network
Your school has an alumni club, use it!
2) Technical organizations
There's a
JUG (Java User's Group) near you! Also check out other technical groups and associations like IEEE and smaller, local ones.
3)Web sites, newsgroups, and mailing lists
I've made money and connections through posting here at JavaRanch!
4) Pink Slip Parties
Here in Boston groups have held pink slip parties. It would bring together unemployed people, recruiters, and a few employers. If there's none in your area, start your own! Pick a place (like a bar, most bars would be happy to host an event at 7pm on a Tue when its usually not crowded) and invite all your unemployed friends and tell them to tell their unemployed friends (or those hiring). Have a signin sheet at the front desk and give out name tags and something color coded (be it the tag, or a wrist band, or something visible), so people can distinguish between unemployed, employed, hiring, recruiter, and other (e.g. VC).
--Mark