A personal favorite idea of ours is the Skill Tree of Life - basically a website where people list their skills and attempt to improve them, themed as an RPG skill tree. This would be a similar idea to Fitocracy, which does an amazing job at keeping you interested in physical exercise. But Fitocracy doesn’t cater to musicians, programmers, and other niche skills that people want to track and show off to their friends. This would be the be-all, end-all of skills tracking and sharing.
Thoughts? Comments? Drop us a line! And as always: if you build it, we want to see it!