The Museum of Modern Art in New York has set up a new place-based learning system for their exhibits. Anyone with an iPhone or iPod Touch can access audio programs for selected art works and various places around the museum. There's even a section for kids! Visitors to the museum use the free wireless Internet to access the site and the audio. I was able to connect to the site using my wireless at home and pretend I was touring the museum. Although I'm sure the experience would be richer if I were standing in front of the actual exhibit as I listened, I found the audio clips - especially the ones recorded for kids - to be interesting and engaging even without the visuals.
If you want to check it out for yourself, visit www.moma.org/wifi/audio/. Since the site was designed for iPhones it may look a little weird but you'll get the idea.