Little things you wear on an ear, then if you nod off (your head tips forward) it beeps in your ear to wake you. [ame="http://www.amazon.co.uk/iSafe-Anti-Doze-Fatigue-Detector/dp/B0060L62YG/ref=sr_1_4?ie=UTF8&qid=1362589073&sr=8-4"]iSafe Anti Doze Fatigue Detector: Amazon.co.uk: Car & Motorbike[/ame] I came across and advert for one in a truck magazine. To me its a bit disconcerting that a trucker with a 44ton load might be relying on that to wake him. :Eeek: Surely if you feel tired enough too wear it you should pull over and have a kip. That said, micro sleeps at the wheel kill people every week, so even though I'd not buy one, maybe they are not such a bad idea.