One of the hardest intermediate steps would be developing a sufficiently large cooperative social unit. Right now I'm typing this on a computer that was made by

One of the hardest intermediate steps would be developing a sufficiently large cooperative social unit. Right now I'm typing this on a computer that was made by people I've never met in a number of different countries that I've never visited; structures like international trade agreements and currency exchange mechanisms make it possible for us to have a mutually beneficial economic relationship. (Size of cooperative unit makes a pretty good benchmark of progress, extending past 1900 to the present.) If technology disappeared, our social and economic organizations would suddenly extend no further than the tribal level, i.e. the number of people we could have cooperative relationships with would be limited to the people we saw in person on a daily basis. Even assuming we still had the necessary schematics to understand what we were trying to build, it would take a long time for us to get sufficiently well-organized to manufacture it in quantity. Of course, it's possible that in this starting-over scenario, technological progress would outpace the rebuilding of social organization, to the point where we'd have all the same electronic goods, for instance, but each region would make its own. Or maybe we'd have to duplicate the transportation-technology revolution of the early and mid-20th century before we could get anywhere with the communications-technology revolution of the last 20+ years.