Soren Johannessen of Microformats.dk and the Danish contributor to Google Maps Mania has created an example Google Map that has Microsoft's Photosynth embedded within the information windows.
Photosynth transforms regular digital photos into a three-dimensional, 360-degree experience. Soren has created three Photosynths of different locations in Copenhagen, Denmark. When you click on a tag on the map you are then able to navigate around various views of the mapped location via Photosynth.
To view the photos you will need to download Microsoft's Photosynth plug-in. It is definitely worth downloading the plug-in as embedded Photosynths is a great way of exploring an area on Google Maps