I darkly suspect William Gibson is a man who really knows his cusps. But I agree, sometimes the apparently trivial changes are actually profound and pervasive in their effect. It's the cigarettes which really give me a period feel in a 70s film - that segment of Cloud Atlas, for example. And the other major one is cellphones. The structure of a detective novel has changed utterly since cellphones. It's also that thing Gibson says in the article - you can predict the tech, but not the use of it. Star Trek had communicators but no Twitter or texting. Weird.