Several weeks ago I re-tweeted Mashable.com's "12 Fun Hacks for Getting More out of YouTube."  Today I learned about EmbedPlus,  a web/flash based tool that lets you do many of the things listed in that article in one easy location.

Simply copy and paste a YouTube URL and then choose start and end points if you want.  You can create your own sub-chapters within the video and also add your own annotations.  Once finished you can embed the updated video to any site (or generate a unique link).  The EmbedPlus player has a few extra features such as zooming, quick replay, chapter navigation (if you created sub-chapters) and related comments (from Twitter and YouTube).

Here's a quick video I made of WIlco's Nels Cline playing a guitar solo.

This would be a great tool for students and teachers because it is so easy to use and to add annotations.  A teacher can assign kids to watch a video on YouTube and to create their own annotations and to highlight scenes that they find interesting. When adding sub-chapters and comments, the video is available in view for pausing and rewinding making it almost feel like a video-editing program.