[This post is by Brad Fitzpatrick, an Android Software Engineer who worries unreasonably about responsiveness. —Tim Bray] Back StoryOne great thing about Google is “20% time”: spending 20% of your time working on projects outside your main focus area. When I joined Google, I bounced all over the place, often joking that I had seven 20% projects. One project I kept coming back to was Android. I lov