FlickrNet is a .NET library for implementing all of the Flickr API's methods. It is designed to reduce the complexity of calling the API, especially with regards to authentication. This library can be accessed from a variety of frameworks and is written entirely in C#.
Taking pictures on your iPhone gives you a great deal of data embedded in to your photos. Location, camera type, exposure, even camera orientation. But what if you want more. Well, MetaPhoto (currently available on the iPhone) aims to further enrich your photos. Using the Urban Mapping API, MetaPhoto looks up a great deal of information about the area a photo was taken and adds it to the photos header.