Spool is a new service (still in an invite-only beta phase) that aims to help you save web content, including videos and articles, to read or watch at your leisure even if you don't have an Internet connection. Spool syncs your content and makes it available to you across all of the devices that you use. Spool can be used as a Google Chrome extension, as an Android app, and as an iOS app.
To use Spool install the Spool apps or Chrome extension on your devices. Then whenever you're viewing a webpage that you want to be able to access at a later time, just click the Spool icon to save that content. Spool can also be used to send content to your Dropbox account.
Here is a video introduction to Spool.
I learned about Spool through Read Write Web. If you go to their article about Spool you can get a beta invite to Spool (this info is current as of 9am EST).
Applications for Education
Last winter my friend Steven Anderson suggested that teachers should try Read It Later to organize and read web content when they have the time to do so. Spool could be used for the same purpose, but it has the added benefit of saving video content for you too.