One example is Flickrvision:
Flickr is an image storage site that allows users to organise their collection of images and share them. Through the use of its Application Programming Interface (API) the content can be used by other sites to create a mashup. Flickrvision is an example of a mashup made using Flickr's API.
It even gives you a unique perspective of the last photos that have been uloaded to Flickr, on a Google Maps, and it even can give you a 3D perspective! That is cool.