More info here.
I made this for those sites that force you to register to view content. I've explained Mailinator in greater detail here. The mailinator home page gives you a random inbox, but selecting it is kind of annoying, and some sites complain about things like using the same first name, last name, username, and/or password. This will give you all the details you need in easy to copy and paste format. The password is a md5 hash of your username, fitted to whatever rules you check. So if you need to remember the password in the future you can just calculate the md5 hash.