Over on Boing Boing Gadgets, our John spotted this vintage wrist-mounted scrolling map from 1927, an antediluvian wrist-mounted GPS:
At first glance, this 1927 map watch is pretty nifty: an antediluvian GPS, don't you know. It was called the Plus Four Wristlet Route Indicator, a name so clunky, unmemorable and artless that it even sounds like the name of a modern GPS device. The idea was simple: the Wooster-esque motorist would putter around England, scrolling a tiny paper map loaded in his wrist as he went with two black knobs. If you took a turn, you simple slid out one map and inserted another one and continued on your way.
What ho! Ingenious! Except a complete road map only cost a few pence back in 1927, where as this device would have set you back around 5 quid. And just like modern GPS map providers, the real business model was in selling you additional maps.
Which leaves the design. I quite like it: it's cheap, but whimsical and adventurous, like something you might strap on your wrist to traverse Oz.