GIS on Google Maps

It is now possible to make thematic maps on Google Maps! Google Map Creator allows one to take ESRI shape files (available all over the internet, just search for GIS data), choose the variable and output one wants, and then creates a thematic map which can be displayed on any website. It is so easy even I can do it! Two of my favorite are the neighborhoods of London and Worldbank GDP. (Hat tip: La Cartoteca)