while we are at it here is the one I used to download (didn't open the comments first) http://guerrillamail.com
But who really cares? It isn't like 37signals is spamming people. As far as less reputable people, I don't want what they're giving away anyway.
I like to use a wildcard @mydomain.com so I can create a new one on the spot and individually track who sends what. If one ever acts up I can just start forwarding that address to the ether. Works well with 1and1's basic hosting plan.
But the majority of people don't.
This is where the email+3ysignals@gmail.com email syntax comes in handy.