Woices is one such project. It allows users to create and share audio snippets linked to a specific geographical location or a real world object. This, however, is where it gets interesting. I would assume that this would mean hearing what the Cathedral de Notre Dame sounds like, but Woices has a very different, slightly artistic, concept altogether. The users record words - perhaps a poem, some interesting info or advice - related to the location in question. It still sounds like a cool idea, but I see this as an unnecessary restriction; why not let people record any sound related to any location if they like?
At Woices, these audio files are called echoes, and the community is called the echosphere. You can search the echosphere through a geographically organized directory or on a map; you can also find out what the freshest and most popular echoes are.
Despite having a cool idea, Woices displays two very common flaws; first, it's nearly empty. Yes, yes, a community doesn't grow overnight, but the site would be so much more fun at this stage if it had at least a couple hundred (instead of a couple dozen) audio files available. Second, most of the files available are named in Spanish. It's not a big deal since the site is available both in English and Spanish, and the default is English; again, when the community builds up, there will be more echoes from all around the world. Right now, though, it will surely drive away some frustrated users who don't understand Spanish.