[david]We have a policy of 1 hour of computer or video game time per day on weekdays for the kids (they get 2 hours on weekends), but they can earn extra time, which they sometimes do, by working on educational software or activities, such as typing for Isaac, writing for David, and Web design for John). One of David’s time-earning activities is to run the Virtual Fish Tank, an online version of the full-size exhibit (once part of the Computer Museum) at the Museum of Science in Boston. Last night he was watching me work (well, play Star Trek Voyager Elite Force II) on one machine, and asked me to call up the Virtual Fish Tank for him. He then said, “I can earn game time just by leaving this running—I don’t actually have to play it, right?†For a 4-year-old, he’s getting much too good at trying to “work the angles.â€