Overlap Maps is a free service that can be used to quickly compare the size of countries, states, provinces, and some bodies of water. To create a visual comparison of two countries select one country from the “overlap this” menu and select one country from the “onto this” menu. The comparisons you make are displayed on a map. You can make comparisons from different categories. For example, you can overlap Lake Erie onto New Hampshire.
Applications for Education
Overlap Maps could be a good little tool to help students can perspective of the relative size of places that they study in their geography lessons.
H/T to Google Maps Mania.