The value of each header was a random quote from the character in question, and you would only get one of those headers at a time. There may have been other Futurama quotes from other characters, but these are the only ones I saw. Crazy.
Here is a sample:
HTTP/1.1 200 OK Date: Tue, 17 Apr 2007 03:16:23 GMT Server: Apache/1.3.37 (Unix) mod_perl/1.29 SLASH_LOG_DATA: shtml X-Powered-By: Slash 2.005000154 X-Fry: I can burp the alphabet. A, B, D ... no, wait ... Cache-Control: private Pragma: private Connection: close Content-Type: text/html; charset=iso-8859-1