Fifty? Try 10. Technological acceptance and growth increases at an exponential rate and everyone my age is just the sort of lazy which wants these things.,(reply>), +Meep “the” Changeling In 10, we might see this replace the tram. Especially in big congested cities like London. Roads could become like slow rail-lines.,(reply>), @IceMetalPunk figured out how to effectively disable me, just send me a link of xkcd, and ill sit there reading it for ever.,(reply>), Nah, just got to wait for the transportation industry to realize this means they don't need to hire drivers (and thus pay ~ 1/3rd of their business costs) and lobby up a storm.,(reply>)," I'd...say 50 is closer. <a href=""http://xkcd.com/678/"">http://xkcd.com/678/</a>"