Sometimes I figure out that solution for some problem I am using is not very common between rest of world, so I will try to share such tricks.
One of them is how do I handle websites that require email address for registration. My favorite way to solve it is to use MailExpire – you simply specify your (real) mail address, when you want to expire temporary mail and that’s all.
For specified time period everything that is send to that mail address (for example firstname.lastname@example.org) is redirected to your real mailbox. You can change expiration if you want or immediately kill that mail when it is no longer needed.