IP Address Lookup
Using IP address lookup you can find where your visitors come from. To find IP address location you may use free online services. You will get:
Geographical location of an IP address
Country
Region
City
TimeZone
Currency
… and many more
Here are some links for IP address lookup:
http://freelabs.info/IpToCountryOnLine.aspx
http://www.geobytes.com/IpLocator.htm?GetLocation
http://www.ipgp.net
http://ip-lookup.net
http://www.melissadata.com/lookups/iplocation.asp
Have fun