Spammers have begun using my e-mail address as the “From” address on spam they send out. This is called a “joe job”, and the only way I know it's happening is, when the spam bounces (for example, when the recipient's e-mail address doesn't exist), the error message comes to me because it looks like I sent the message.
If you do receive spam that appears to come from me, or any other spam, I encourage you to use SpamCop to help you report the spam to the ISPs where the message originated. Don't bother complaining to me, since there's nothing I can do about it.
If you're feeling more aggressive, find out if there are laws where you live making it illegal to send you spam with forged headers (in this case a forged From header). If so, take whatever legal action is available to you. If not, write to your Congressmen (or MPs or whatever applies to you) and ask them to make it illegal, and to impose stiff sentances for convicted spammers (jail time would be a much more effective deterrant than monetary fines). The war against spam must be fought on many fronts - technical, social, and legal.