For a guide to science sites in Philadelphia, see the following article in the Physical Tourist section of “Physics in Perspective“: Paul Halpern, “Philadelphia: Life, Libery, and the Pursuit of Physics,” Physics in Perspective 11 (2009), 209-227. “Physics in Perspective” regularly publishes such Physical Tourist articles, 31 of them since 1999, about half of which have been reprinted in John S. Rigden and Roger H. Stuewer, ed., The Physical Tourist: A Science Guide for the Traveler (Basel, Boston, Berlin: Birkhäuser, 2009). Available from Amazon UK and Amazon US.
One of our recent projects has been to launch a Travel Guide, an online guide to history-of-science locations around the world. The guide is aimed at the general public as well as specialists and has been consistently receiving 5000+ hits per month since its launch about a year ago.
We would love to highlight Philadelphia-area sites ready for the 3 Societies conference in July, and so we are putting out a call for articles. Articles need to be about 500-1000 words long and we have a guide for contributors which provides full guidance for potential authors
See http://www.bshs.org.uk/travel-guide/call-for-articles for further details.