Sunk a lot of time researching and then trying to implement Mac OS X application sandboxing today, only to strike out. While watching one of the WWDC 2011 sandboxing videos for the third time, I saw Apple Events mentioned in the presentation. Slowly realized I was looking at the clue I needed to unravel a feature for SleepMute that I've poured many man-days of research into. With that clue, the rough version of this new feature was done in 40 minutes!
If that's not programming serendipity, I don't know what it is.