Google’s dirty little secret talks about how Google determines whether your site appears on top for a search depending on whether you and the searcher are in the same geography or not. So if your server is in Kazakhstan, expect fewer hits.
Dodgeball lets you broadcast your location to friends via a mobile. The interesting thing is, Google has bought Dodgeball.
There’s software that can locate where you are using a photograph of buildings.
Google lets you search by location in the US. via GoogleBlog
Geobytes is a piece of Javascript you can insert in your page, that will show visitors where they are from. via FilterCoffee
Experimenting with GeoURL. It also gives an interesting perspective of blog usage, geographically.
With network-tools, you can find out where a particular computer is, who’s it registered with, and how information travels there.