Reply to post:

25 years or so ago I gave my nephews Sony wristwatches.........didn't take them long to realise they could be used as remotes for the display screens in their school classrooms. Chaos and hilarity ensued, with the kids switching programs mid-lesson. Took ages for the teachers to work out what was happening. Retribution was swift when the did work it out: detentions and confiscations ensued, and Sony watches were banned