Of course, in reality, you need to give other people an EMail address where you can be reliably contacted in spite of the fact that every time you do so, that address might end up on a mailing list eventually. Until the various governments and Internet consortiums finally get a handle on this plague, the only interim solution is to maintain two EMail addresses - a public one that you post on website Forums and use for ordering online that you only monitor occasionally, and a private one that you give only to friends and family that you check regularly.

Try http://www.mailwasher.net for help if you receive your EMail through your Internet Service Provider (ISP) and they don't provide any SPAM blocking.

The head of Google's webspam team, Matt Cutts, recently posted a great article on stopping SPAM on his blog. He mentions several services that are free or low-cost.

Check out the Federal Trade Commission SPAM Information to keep abreast of legislative efforts to stop SPAM.