I have an image and I want to search to see what it is. Any API's available for that?
I believe there are quite a few. You want to search for Content-based Image Retrieval (CBIR). Wikipedia has a page of CBIR engines, including an extensive list of open source ones. For example, isk-daemon and LIRE are both open source CBIR libraries:
isk-daemon is an open source standalone server and library capable of adding content-based (visual) image searching to any image related website or software.
The LIRE (Lucene Image REtrieval) library provides a simple way to retrieve images and photos based on their color and texture characteristics.