I've never really needed it but I've been looking for a tool that is super easy to use that quickly looks up the location of an IP address. The super easy tool is called hostip.info and this is what happens when you do a lookup on www.peterbe.com's IP at http://api.hostip.info/get_html.php?ip=80.68.212.7 :
Country: UNITED KINGDOM (UK)
City: (Unknown city)
Cool. I'll remember that till next I really need this. I discovered hostip.info by reading this cool blog by Corey Goldberg
Try `whois 80.68.212.7` for a change... requires more reading skills, but gives vastly more information too.