Pick a year: It’s easy to look back and convince yourself That Was The Year That Was in tech, partly because the pace of change is so rapid and partly because we so readily embrace and then quickly depend on things that are completely different. Consider this: When the class of 2012 was applying to college, there was no iPhone. Until those students were just about at the end of their junior years, there was no iPad. Both of these nascent devices now define the mobile Internet, which is where all the action is.

But 2011 had some pretty remarkable advances that seem to be the start of inexorable...