Too bad no one has servers in 100s or even a 1000 or more ISPs in dozens of countries with TCP connections to a statistically significant portion of the Internet on a daily basis who could possibly measure, say, RTT (not sure why TTL is relevant) and other things, and perhaps use that along with other information to create a database that they could then give to customers who need geo-location data for their "mission critical" applications.
Unless I'm mistaken you do (or at least as close to it as anygone got) and that is one of the basis of your service!
That would probably be pretty darned accurate.
The point is it probably would not be as accurate as one could hope because internet network infrastructure is network-centric and not necessarily region-based. Of course you could try to fully map INET like CAIDA does and keep the info updated on "daily basis", pretty hard work though...
Of course, that would be a "commercial service".... =)
Certainly having to support machine on every large network in every city is rather troublesome otherwise. Of course this is probably way overkill for IP->Country data. -- William Leibzon Elan Networks william@elan.net