People have Jetpacks that do everything from extending the capabilities of the web to adding a Cylon to the browser; from taking snapshots of the current page to controlling music players. In fact, we've had over 40,000 downloads and over 40 Jetpacks (that we know about!) written by people who previously had only written for the Web. And Jetpack is still mainly a technology preview.
# Turn social bookmarking and page annotation into effective learning tools (for example by including peer-assessment features).
# Allow users to easily compile personal e-portfolios (for example, by combining their own works - photos, comments, articles-with testimonials others have written about them).
# Let the browser suggest relevant materials (for example, by automatically identifying additional articles based on what sites a person visit or which topics they search for).
# Support social learning communities (for example, by making it easy to find and connect with others who share similar learning interests).