I was seriously looking at stauns after Bobp lent me his and I sat around drinking beer while they let all 4 tyres down for me by themselves
actually there was about six of us standing around going 'hmmm tyre deflator gooood' like we'd just discovered fire or something (obviously my mates aren't real high up the food chain either), but I will vary my pressures and don't want to fart around calibrating them.