Impossible for the HN crowd: Do nothing for 2 minutes
I was just thinking about the fact that much of my work requires me to pause for a short time -- while building my project, or running a query, or launching the huge honkin' java webapp and waiting for 10 billion classes to initialize -- but the pause is too short to make a useful context switch, and too long to simply wait through without getting bored. So typically, I often check e-mail, HN, or whatever, but then end up getting sidetracked. Being able to simply wait through these would be great. Unfortunately, developing this sort of mental discipline, along with exercising, making my bed, and eating out less often, falls on my "Things That Are Good For Me That I'll Probably Never Do" list.