Digital magazine from Stanford University highlights interesting and challenging stories of innovation. Could be a great kick-starter for project-based learning or to engage kids in innovative and critical thinking.
The DIY online club awards badges (called 'Skills' on the site) to students and kids of all ages in exchange for completing tasks. DIY Makers share their work with the community and get patches for the Skills they earn. Each Skill consists of a set of Challenges that help them learn techniques to get the hang of it. Once a Maker completes a Challenge, they add photos and video to their Portfolio to show what they did.
This site lets users create informative, web-based graphics using images and "tags", which function much like people tags in Facebook. Thinglink has the advantage, however, of allowing tags to contain links, media, etc.