The Embedly Objective-C SDK by Embedly allows API interaction. Its resources include embed and extraction of APIs. An example demonstrates how to embed images to a project that a user can re-size and crop.
Uberblic is another instance of what may become a trend in the world with thousands of APIs: the Meta-API. The Uberblic Doppleganger API is currently in beta, but it is quite ambitious in that it looks to position itself as a API cross-reference or mutli-plexer. Submit an ID from one API to the Doppleganger, get 4-5 IDs for matching content from other APIs.
vjoon K4 has just become the first publishing system to support full integration with Adobe's New Folio Producer API, a set of APIs that are available as part of the Digital Publishing Suite (Enterprise Edition) to Adobe Technology Solution Partners.
Diffbot is one of the coolest new ideas on the internet. The service brings monitoring to the web in a new and interesting way. The company is just about to release a whole slew of projects built on its collection of Diffbot APIs for following changes to web pages and RSS, as well as extracting clean text from websites.