Well, that's a pretty neat site, but ... ironically it couldn't locate the IP that's been bombarding my servers with PROPFIND based DoS attacks ;-) Which I located easily through RIPE.NET earlier.

Admins can and do routinely look up IP's in the Whois databases to find out the ISP of someone who shows up in their security logs, but we don't usually care where those people are physically. I got the inclination to block out the entire non-US set of IP's because our servers only really care about traffic from existing and potential clients, who are all going to be located within 100 miles of us due to the nature of our business. So I'm just going to block at the router or firewall level all packets from non-US IP blocks. Should drastically cut down on the security log work.

- Qualm