[mhd]

I would say that you also need "3. Groupies". I really dislike the "rockstar" moniker, but positive reinforcement is important, especially if it appears as if you're stuck. That's one of the good things about the open source world, where it's easy to have a small, popular project. The sheer amount of project and time management skills teaches you is much greater than the improvement in coding ability (which really isn't that linear).

If you do a decent job of presenting and updating such a project, people will like it and probably let you be aware of that fact. And even the most lone-wolf programmers need that, whether they admit it or not.

This could be done at work, too, by making some utilities or introducing new features for the benefit of you co-workers or customers. Most of the time, the feedback isn't as direct, though.