In Chicago, its been my experience that arguing with a cop is a BAD idea at any time, whatever the actual law. I've used my tripod all around the city, and maybe just got lucky, but have never had a problem. I have, however, been stopped from just taking "tourist snaps" without a tripod at the train station because of "security concerns." Shedd Aquarium does not allow using a tripod, which seems reasonable with the close packed "schools" of tourists. The Field Museum allows cameras except for special exhibits. Supposedly one can obtain a free tripod permit from the information desk for the regular exhibits. [I want to try this on my next Field trip, as some of the Native American artifacts are very dimly lighted.] The Art Institute does not seem to allow cameras, period. Sketchbooks and pencil are OK, but you need a permit to set up an easel. Apparently this permit is rather easy to get, as I've seen lots of folks painting the paintings. So far, none of the residents at the two local zoos have complained about cameras or tripods, and are generally quite happy to pose. Some of the links I've included here are informative. Perhaps the mods would like to add a couple of them to the resource area, as this topic seems to come up a lot. But always remember it is a VERY bad idea to argue with a cop. http://www.boingboing.net/2005/05/27/chicagos_bean_sculpt.html http://www.rcfp.org/photoguide/ http://www.krages.com/ThePhotographersRight.pdf http://www.mobar.org/press/medhnbk3.htm http://www.usatoday.com/tech/columnist/andrewkantor/2005-12-29-camera-laws_x.htm