Fun ways to turn down recruiters

A coworker of mine got an email with a perl script the other day from a recruiter.  The script didn't work, but the code implied that the recruiter wanted to tell him that his salary would jump 100k with his help.  My coworker sent him the following in his response:

perl -e "print (join '', (map chr, (78, 79, 33))) while 1;"

Another valid response that I composed was this:

printf '\x4e\x4f' | xargs yes 

How do you turn down recruiters that you don't like?