For its Documerica Project (1971-1977), the EPA hired freelancers to photograph "images relating to environmental problems, EPA activities, and everyday life in the 1970s." The photos have been posted to Flickr as part of the US National Archives Flickr stream (link goes to their sets). Like many of the collections public institutions have made available at the Flickr Commons, they make for good browsing.
(photo: Ernst Halberstadt)
I remember sitting in cylinders like these. They were fantastic. I haven't seen any in a park in a long time.
A 1973 electric car that looks a lot like the current Smart car:
Load any one set and be bathed in the dimly bright coolish warmth of the 70s-photos color palette: (for example).