The Gates Foundation gets into the act in a big way. I especially liked the comments on using retired principals or teachers to review video of teacher performance. Why not expand that to parents as well?
One of the craziest mismatches in education is the number of people who want to help their kids vs. the number of people who can improve what goes on in school. Video allows time-shifting and space-shifting, vastly expanding the pool of people a principal could draw on.