Tyranny of email - and warping
Thanks to Ned for sharing this link to The Tyranny of email. It contains some good thought - like the three hour rule:
I maintain that programming cannot be done in less than three-hour windows. It takes three hours to spin up to speed, gather your concentration, shift into "right brain mode", and really focus on a problem. Effective programmers organize their day to have at least one three-hour window, and hopefully two or three. (This is why good programmers often work late at night. They don't get interrupted as much...)