Just for fun: Lunchtime-Stretching Clock
Man oh man, I can't really say this is a "product design" or "usability" thing, but it's too good not to post. Randy Sarafan has a complete how-to guide at Instructables for making a clock that sneakily stretches out lunchtime, by speeding up 20% at 11am and slowing down 20% at 11:48am. That's an extra 12 minutes for your break - and who could argue with the clock on the wall? It's clever, subversive, and a worthy Arduino electronics project - so in that sense, well-designed!