In the case that I have uploaded an image and just wanted to tag a certain section of the image like facebook and flicker with meta-data. It would be highly useful to have the ability to for example use a highlight tool and select a certain part of the image and through the box coordinates.

Logic:
After insert of the annotated box at 400px x 300px of Resource(image) , allow user-specified pop-up to appear and allow user to insert tag at resource coordinates.

Now if we move into video and annotating video, you can check out popcorn.js:

http://popcornjs.org/