Space elevator concept art (1970) and the Flying City Of Venus (by S.Zhitomoirsky, 1971) from the magazine "Technika Molodezhi" (Youth Technics) - via io9's groovy socialist world of 1970s Soviet futurism.
Here's concept art from a Japanese adaptation of EE 'Doc' Smith's Lensman books. I'd love a good big budget Lensman film. I promise not to be hyper-critical of the things they get wrong. Via Dark Roasted Blend's Facebook account.
A few random, third-hand photos via the H.A.M.B.
And, to wrap it up, one from Flickr. As usual, you can click through to see the photo and find others from the source photographer.