If you point your browser to http://mailcatch.com/en/temporary-inbox-hosts you will notice MailCatch now allows you to make one of your domains point to it and it will eat spam all the same! I have registered two new domains (ieatspam.info ieatspam.eu) they should appear on this page in a few hours/day once the registration process is complete.
So if you have some domains lying around you can use them to help people fight spam!
It should also accept A records (IP addresses of mail.mailcatch.com) -- and send an email to the donor when/if the server's IP address will be changing