I started Learnstream to supercharge my studying in college. Since then, its experiments with learning from video and spaced repetition have helped make a professor into a YouTube celebrity, gotten the attention of Bill Gates, and helped students transition to Harvey Mudd's brutal physics program.
Geknowm was a little startup tackling a huge goal: mapping human knowledge. We started with fun quizzes on common knowledge and the news. Geknowm tracks your knowledge in various topics over time as you answer questions.
My wiki started to track my first year in the Carnegie Mellon PhD program: highlights and summaries from papers I was reading and notes on my own research. The wiki uses researchr, but I added several extentions including a frontpage that visualizes my changes over the week.
If you need a fix of academic papers on learning science and human-computer interaction, head over to the Effective Learning wiki.
Working with non-profit company Quill, I developed Flash Feedback to provide instant feedback on simple writing prompts. The magic of this technology is brought to you by advances in natural language processing via LightSide and the crowdsourcing enabled by Quill's platform.
Shuff is an experiment in killing the to-do list via randomness and personal analytics. The web application provides a dashboard representing what you've done that day. If you see something you want to change, do it! If you aren't sure what to work on, Shuff can give you something random to do for a fixed amount of time.
Shuff your day at http://shuff.herokuapp.com/