Yahoo! recently launched a new map overlay tool called MapMixer. The mashup site allows you to upload an image of your own map and use Yahoo!’s tools to georegister it with Yahoo!’s maps. This allows you to view your own maps along with Yahoo!’s maps and take advantage of the pan, zoom and other functionality provided by Yahoo! Opacity can be adjusted as well as the ability to scale and rotate your map. You can also share your maps with others and there are other community building functions such as rating and commenting on uploaded maps.