GMail Invites

ONE PER PERSON. Once you have one account, you'll be sent invites, where you can then invite yourself to add another.

And, please, make sure you're actually interested in using the thing before taking one of these. (Ie, don't do what I did.)

http://gmail.google.com/gmail/a-846db11fb5-f19f5e09a1-74e6c0282b
http://gmail.google.com/gmail/a-846db11fb5-6947b8d496-81e55cbf46

Just replace the first name / last name / secondary email address with your own.