Networking

This site is a great way to network for information and even to hook up with other professional to swap or even for job opportunities, but I'm wondering if anybody else uses groups such as BNI or the local Chamber of Commerce.

So far I've found these groups to be a great place to market myself, get referrals, build a decent reputation, and  even as a support group to help me in areas I'm still trying to figure out.  

So my topics for discussion:

How do you Network?

Where did you find out about these groups or events?

What has been the best part of your networking experience?