Our principal recently bought 20 pairs of camera glasses. They look like regular glasses (although a little heavier than normal), but have both a camera built in, and a microphone, as well. I bought two pairs, one for my husband, and another for me. We've been using them, and the effect on behavior of students is interesting.
The majority of the students act better when they know they are being recorded (or think they are - it isn't necessary to have them recording at all times). However, the truly - well, let's call them "challenging" students - often act even worse, at least at first. Some of them eventually settle down. Others never do.
However, with MOST of the class improving their attention and behavior, it's still a LOT better. I got more teaching done in the last week than I have in months.
They are definitely a keeper.