Earlier this week Microsoft announced that it is making some of the imagery used in its Virtual Earth platform available for purchase (more on Virtual Earth in our VE SDK profile). The imagery, taken with Microsoft's proprietary UltraCam shown below is available for approximately 200 cities (in high resolution and averaging less than two years old).
Kooaba offers image recognition through its Kooaba API, allowing you to compile metadata on objects in your photos. This can be used for product recognition and pricing, but could also be used to augment personal photo collections, which can be so large that they are nearly impossible to search by hand. There are tons of use cases for image recognition and this API should really open up the field and bring more applications to market.