You may not realize it, but it’s quite possible to get a very good idea of where you live just from your IP address (your computer’s numeric address on the Internet). Want to see where “they” think you are? Visit this page (you don’t need to type anything in; “they” already have all the information they need to locate you).
The provider of the page above is MaxMind, one of a number of commercial outfits which provide this “IP geolocation” service. MaxMind’s service is called GeoIP. Based on my IP, it seems to be more accurate than competing offerings from IP2location and Quova.