Have you ever wondered how you get spam? Now you can find out where it comes from. The first step is to get a free Gmail account.
Gmail was in beta for two years and it was a major status symbol to have a Gmail account because you could only be invited to get one.
Now that it is out of beta, anyone can get a free account.
Gmail has an interesting quirk in which you can add a plus sign (+), followed by any additional text, after your Gmail address, and it'll still get to your inbox.
This feature is called plus-addressing, and it essentially gives you an unlimited number of e-mail addresses to play with. The really cool feature is that all these new addresses you make up on the fly come to the SAME inbox. The major difference: You can see which plus-address it was sent to, and therefore know where the e-mail came from.
The easiest way to do this would be to use the name of the company or service you were signing up at. Say your address was John@Gmail.com and you were signing up at Monsanto. You would simply sign up as John+Monsanto@gmail.com and it would still come to your inbox.
The difference: If you started receiving e-mails to that address from companies other than Monsanto, you'd know Monsanto sold your address and was spamming you.
The beautiful thing about this system: You could put a filter on those plus-addresses so all of them would go into your spam folder and you would never have to see them again.