Transparent Map Comparisons
Imagine a world where Google Maps had cycle routes!
This map mashup allows you to compare Google Maps with OpenStreetMaps. It is possible to select from Google Street maps, satellite imagery, topographic maps and Yahoo Maps as a base layer and then view various OpenStreetMap layers superimposed on top.
The map includes a transparency slider so it is possible to adjust the transparency of the base layer and the overlay. So if you want you can pretend that OpenStreetMap has great satellite imagery or pretend that Google has great cycle maps.
The application even comes with a permalink option so you can send the current view of a map to friends and colleagues.