Check out the FotoTag WordPress Plug-in
P.S.: This item is no longer supported or updated.
Overview ImgTag is a script for adding tags (annotation) to your images. With ImgTag the user can move the mouse over specific regions in your image to see a tooltip or a custom effect.
Features
Extremely light-weight (around 5Kb compressed) Easy to use. Very simple and clear JavaScript syntax Fully customizable through CSS or JavaScript Facebook like tagging: Hover over links to highlight the tag Photo Fade Effect to better highlight your tag Cross-Browser and Extensive documentation
Make sure to check my other script and my online qrcode tool