Origin: USA, Chicago
from John, at www.exposingmyself.net

Origin: Germany, Berlin (full size)
Flickr image by ickbins

Origin: USA, California, San Diego (full size)
Flickr image by sportyjac22

This one is not really visual but pretty interesting sign. (tells a lot). Another all time favourite: At a distance, objects become smaller

Origin: USA, San Francisco, flickr image by Mòni, (full size)

2in1, schematic anthropology and realistic zoology, the contrast pretty strange.
Origin: South Africa, by Otherdave, (full size)