If you ever want to want to see what are your friends’ favorite places, where they spend most of the time, then Creepy is your best bet.
Creepy is an online tool, that makes stalking easier, it aggregates Twitter (and Flickr too) location data and shows you where the person had been.
To track a person, all you need to do is, enter his/her Twitter handle, use the search if you don’t know his Twitter ID. Wait for sometime till Creepy aggregates the location data.
In the map view tab, you can see a list of coördinates of the location where the person had been, click on an item to see the same in Google maps. You can also get the satellite view, for that, go to Creepy > Map source > select the view you want.
Note that, if the person you want to track uses Foursquare, then his check ins (in Foursquare) will appear only if he had tweeted about it. The developer could make the app better by adding Facebook as a source for location data.
There is an advantage of using this tool, as in you can actually enter your Twitter handle to see how much information you are leaking about your whereabouts.
Do drop in your comments.
Link: Creepy