"After writing the above piece, I remembered once using a nifty little tooled called 'netdemon'. Its a windows(god forbid) tool, but I fired up a computer with windows, and downloaded the tool.
"Using the 'address scanner' you can reverse-resolve any IP range. Since I've yet too see such a tool for *nix - I fired it up, and found the list. I suggest that you other slashdot guys do the same. You'll find the tool at www.netdemon.net" - Rune Kristian Viken