RE: Is anyone else getting DoS'd by relay attacks?

I have been getting buried under backscatter since about Dec 1st myself. 
These messages come from non SPF aware mailservers by definition and are 
readily identifiable by the fact that they are being bounced to blatantly 
fake nonexistent usernames on my domain. My mailserver originally rejected 
those with the default comment but I have changed it to specifically pick 
out that backscatter (about 99.9% of the traffic arriving at my server alas) 
and reject it with:
550 Recipient address rejected: Recipient unknown. Please consider 
implementing SPF (http://spf.pobox.com) to avoid bouncing mail to spoofed 
senders. Thank you.
The way I see it, why shouldn't the spammers advertise SPF for us thousands 
of times a day? With any luck some small percentage of mailserver admins 
will look at their logs, notice one of the messages, and say "SPF, what's 
that?" and look into it. I imagine it'd make a much bigger impression if 
someday they saw not just a couple rejects imporing them to use SPF, but 
dozens from many different other mailservers.
I'm in the middle of typing up some instructions on how to configure a 
mailserver like mine (Postfix using recipient map checking) to do this, and 
was going to submit it to be placed on spf.pobox.com so others can benefit. 
I'd like to include information on doing it on as many different setups as 
possible so if anybody else with a different system has done the same thing 
or figures out how to do it, let me know. Thanks!
--Kaas