So what can you do ?

• Boycott spammers. Do not buy their products. Complain to them.
• Use filters. Some Spam is recognizable algorithmically, e.g. by who sent it, or the subject line, e.g. 'MAKE MONEY FAST'. Note that this method could filter out valid email if you are not very careful.
• Don't publish your email address more widely than necessary. You can use a comments form on your web pages.
• If you want to post your address to newsgroups or mailing lists put in some obvious 'take out' such as 'NOSPAM', e.g. me@home.NOSPAM.com; people will recognize what to do, hopefully Spam bots won't (for a while, at least).
• Most Spam email comes with an invitation to 'remove' yourself from the list. Don't believe it! These almost always bounce, and apparently might also be used to harvest new addresses.
• Learn how to read headers before you complain to/about the wrong people. Headers which will quickly point out forgeries include Path, NNTP-Posting-Host and Message-ID. If you get a forged message, please report it to the postmaster or abuse account on the site from which it originated.