Web application for visual comparison of geographic areas?

Question

Does anybody know a web application (like a Google Maps Mashup) that allows putting maps or city/area outlines on top of each other to get a feeling for the area's dimensions?

Say, you want to know how New York is. You drag & drop an outline of your home city on top of a NY map, which can help get a feeling for the city's dimensions much better than numbers.

I found a web log entry that illustrates what I would like to see as an application of some sort. The true size of Africa

Answer 1

http://mapfrappe.com/

This Google Maps mashup lets you see an outline of one part of the world overlayed on another part of the world. For example, you can sketch an outline of California in the “Reference Map” below, and then overlay the outline over Japan in the “Comparison Map.” Whatever you draw in the top map stays centered in the bottom map.

Hope this helps.