One of the (very many) things that annoys me in the IT world is spam. Even more annoying is working out which of the multitude of Web forms I've filled in has then either had its mailing list stolen or sold.
Most of the time I don't bother - I add my Gmail account as the e-mail address to the forms. However there are those Web forms that don't accept hosted e-mail accounts and want you to use your corporate or personal e-mail address.
If you can easily add e-mail aliases to your corporate or personal e-mail address then you might be interested in the following technique.
I run my own mail server, so I've recently taken the step of adding a suffix of ".spamtrack.source.<website>" to my business e-mail address to create a new alias, where <website> is the site that wants my business e-mail address.
So if my e-mail address is email@example.com, then my new alias for a Microsoft Web form becomes firstname.lastname@example.org.
It's a bit longwinded and fancy looking - I wanted something that looked like an automated system handles it. It also means I can add that later if I bother scripting something to take care of it and auto-mail abuse@ to tell them that my e-mail address has either been stolen or sold. I could possibly even extend it to be something like email@example.com.
So now I'm able to see who's selling my e-mail address or who has had their mailing lists stolen. And if the spam levels climb up, then I can simply kill the alias.