I noted before that the Museum of Modern Art (MOMA) is using podcasts to provide audio tours for patrons. I'm pretty sure that renting an MP3 player and listening to an audio tour fails one of the basic tests of podcasts (there's no subscribing going on), but hey - it's for art so I'll let it slide.
Apparently the MOMA isn't the only museum doing this. The New York Times has an article that talks about The Metropolitan Museum of Art and the venerable Panhandle-Plains Historical Museum also using podcast technology.
The interesting thing isn't the technology itself, it's how it's being used. The Panhandle guys have made an audio tour of a recent exhibit Sharp Horns, Soft Seats available on their website. It sounds a little odd to download an audio tour of a place that you're not actually in, but it gives a surprisingly good feel for the place.
Interesting marketing tactic.