If you intend to find meaning in your 20% time I would advise you to find a way to make your project fit in to some greater picture outside the company. The FOSS community has seen a lot of side projects come out of Google and wither in a world that can’t really take advantage of them. Finding collaborators within Google should be a lower priority. It’s not quite as self-directed but you still have great latitude in choosing what to do and a better shot at making an impact on the world.
