I'm not sure why, but www.linkrink.com has been down for a few days. That tool would allow me to paste many domains in a single box, click "Go," and it would instantly tell me the total number of unique IPs amongst all of the domains. Here is the archived page: http://web.archive.org/web/20070501211821/http://www.linkrink.com/ Is there another tool like this online?