xRez has some stunning, large (gigapixel-sized) panoramas that you can zoom into using the Google Maps interface. It’s similar to the Gigapixel project, I think.
Panoramas on Google Maps
I found some stunning gigapixel-sized panoramas at xRez that use the Google Maps interface for zooming. These high-resolution images are similar to the Gigapixel project and offer an incredible level of detail.