Among the most exciting PopTech conference moments are when the Fellows each give a glimpse into their compelling work — and how it might change the world. The Fellows’ 2011 presentations are now available online so you can revisit those you savored and catch up with others you might have missed.

This year, the 2011 Science and Public Leadership Fellows shared their breakthrough work in areas including autism, robotics, infrasound, environmental bioremediation and more.

The ambitious initiatives from the 2011 Social Innovation Fellows ranged from local food networks to pay-as-you-go solar energy, and from keeping girls in school to building community through music and architecture.

Check out the Fellows’ big ideas and keep an eye out as their promising efforts continue to make great progress.