Pipette is a mini application that serves only one real purpose: grabbing colour from any part of your screen. The interface is quite simple and choose a close up view of your screen, from which you can select any pixel. Pipette will displays HEX codes and will work whatever application is open at the time.
While any well-respected image editor or retouching application is already fitted with a proper color picker anyways, Pipette can be quite useful to grab colors from anywhere, and it avoids the pain of having a bigger application all the time. If you're into designing or retouching images this could prove a useful arsenal to your set of image and drawing tools.