MarkUp.io - Draw On Any Webpage

Markup.io is a free service that enables you to quickly draw and write on any webpage. Markup.io operates as a bookmarklet in your browser's bookmarks bar or toolbar. Once you have Markup.io installed just click it anytime you're viewing a webpage to start drawing and commenting on that page. When you're done marking a page you can share it with others by clicking publish. Publishing creates a screen capture of the page with your drawings and comments. That screen capture is assigned its own unique url that you can direct others to.

Applications for Education

Markup.io could be useful for commenting on and critiquing online articles then quickly sharing your comments with others. Students could use Markup.io for news articles. Students could also use Markup.io to comment on images of famous landmarks. You could have students find an image of a famous landmark and write a few facts about it.

Here are some related items that may be of interest to you:
3 Web-based Tools for Creating Screencast Videos
Using Screen Captures to Enhance Instructions
Bounce - Share and Collaborate on Screen Captures