The 500px Ruby wrapper by Chris Micacchi has been designed to interact easily with the API capabilities of search, retrieve, and upload photos. It aims to reuse HTTP connections. 500px is a community of photographers who can showcase their projects, discover new photography styles, and find royalty-free art.
Magickly aims to make image manipulation possible as a simple web service. The Magickly API is very easy to use, and completely open source. It requires no API key, and allows a developer to use a lot of different image manipulations on any web-accessible image. Magickly is an open source, simplified version of the Aviary Effects API, which has a contest ending next week.