Yesterday I received an e-mail from a friend, complaining about being deluged with spam e-mails after he provided his address to a software registration site. I asked him why he hadn't used a disposable e-mail address, but to my surprise he hadn't heard of them.
For the benefit of those who've never used them, Wikipedia describes them as follows:
Disposable email addressing (DEA) refers to an alternative way of sharing and managing email addressing. DEA sets up a new, unique email address for every contact or entity, making a point-to-point connection between the sender and the recipient. Subsequently, if anyone compromises the address or utilises it in connection email abuse, the address-owner can easily cancel (or "dispose" of) it without affecting any of his other contacts. Following the cancellation or replacement of a disposable email address, the (ex-)owner need notify no more than one person/contact of the change.
There's more at the link.
A large number of sites offer DEA's. Two articles from Digital Trends and About.com offer brief reviews of a number of them. Pick one that sounds good to you, and use it to confound spammers. They deserve nothing better, and (IMHO) should receive much worse!