May 26, 2011
Google Cloud Vision API is a REST API that will help developers analyse images like never before. It supports various features like Entity identification, Facial Detection, Landmark Detection, Logo Detection, OCR and Identifying Explicit content. It is available in Limited Preview for now.
There are any number of questions that can be answered by Wikipedia, but you can add "where am I?" to the list. Given any latitude/longitude coordinates, the WikiLocation API will find you corresponding Wikipedia articles to tell you about your surroundings.