A personally beneficial result of the recent (and misguided) public handwringing over the way Gmail handles dots is my discovery that it also ignores everything after a '+' in the local part of your address. There are two useful applications of this feature:
This isn't exactly a original thought, which is demonstrated by the availability of numerous disposable email address services.
The bad news: a lot of web apps -- most? -- reject or mishandle e-mail addresses that contain a plus sign. Cingular rejects them. Bank of America's site rejects them. Flickr gets it right.
The worst offender is Ebay, which silently stripped the plus sign from my address and sent the change-of-email confirmation off to some non-existent inbox.
If one were the type to reference standards documents, one might point to RFC 2822. If one were so inclined.
Ok, so I wanted to try this earlier, but had to run off to class. You can try entering the hex encoding of the plus sign (0x2b) in place of '+', but it's hard to say how that will turn out for any given web app.
For example, I finally got Ebay to accept the plus sign by using myaddress%2bebay@gmail.com. I did get the confirmation e-mail. But the confirmation page -- the page you have to click through to confirm your new address -- once again stripped the plus character and, this time, put a space in its place. This page then rejected myaddress%2bebay@gmail.com, complaining that it didn't match the address I'd originally entered. This page did accept the plus sign. Ugh.
Cingular's site is hopeless. Their JavaScript always complains about the plus sign. My tests in Internet Explorer indicate that in that browser you can't even enter a plus sign. It's ignored. If you disable JavaScript, you can get to the next step, but then the site silently strips everything after the plus anyway and sends a confirmation e-mail to the resulting address. Double ugh.
Bank of America's site isn't any happier about '%' than it is '+'.
Oh, and PayPal gets it right.