A handy little php/mysql utility to replace that piece of paper/Excel spreadsheet with you IP address information.
My only gripe with it at the moment is that you can’t populate the “Description” field from information that pops up as a result of a reverse lookup.
Still, easier than using a spreadsheet. A big plus is that you can get it to scan an IP range and do reverse lookups. You’ll get a tick next to the IP if there is a reverse-lookup DNS entry for that host.