Also announced last week, a beta release (of course) of Yahoo’s MapMixer tool, which allows you to overlay an image atop of Yahoo’s mapping engine. It seems analagous to Microsoft’s MapCruncher, which was released last year. Yahoo! Local and Maps Blog:
[A]nyone who has a map in .jpeg, .gif, or .png format can now upload their map onto a background of Yahoo! Map and mix it, blend it, or customize it. The app gives users tools to adjust transparency, pin-point chosen locations for accurate overlaying and placement, stretch, rotate, zoom, and pan.