Google Maps Transparencies

Google Maps Transparencies is a nifty little application that I discovered today (via Stumble Upon)
A transparent Google Map is overlaid on top of the equivalent satellite image. The transparency of the map layer can be adjusted and is particularly useful when looking at street level in high definition cities like London. A similar feature has been around for quite a while in Multimap, but this mashup is rather more flexible. The view can be toggled as shown in the screenshots. A very useful application, and no adverts or other distractions either.