This looks like a pretty cool little tool. You can create an up to 3 minute screen capture with sound and either send it in twitter or email.
Just launched yesterday Screenjelly is created by the people at Screentoaster who I've written about previously. I just tried something quick, and the quality looks good. There are lots of ways you could use this, but for education here are a couple: If you have an online course and one of your students is having trouble with an application. You could have that person create a screenjelly. In minutes you could see the exact problem. If you are writing a blog and want to show your reader a concept, screenjelly might be helpful. Check out this interesting ScreenJelly from Bensykes where he demos photo realism in a desktop resume.