I like to share my own recordings of the places I traveled to in the 'Places' category. I've been thinking of creating a system to collaboratively share these 'sonic pictures' from all over the world. It would be very inspiring to be able to listen to any part of the world.
But it seems I'm too late! SoundTransit, a project created by Derek Holzer, Sara Kolster and Marc Boon, does exactly that. You can search for sounds by keyword, country, city. You can also book a transit: choose your point of departure, a destination and an amount of stopovers, and your journey will be ready in a moment. I just went from Marrakech to Antwerp via Vienna. It basically just crossfades the files, but it's a nice idea.
If you make field recordings yourself you can contribute to the project. You'll have to send an email to the creator of the site with some information about yourself in order to become one of the 'artists'. I really like the idea of Soundtransit, although I would personally prefer a site with more user interaction, more like a social network. It should be easy for people to participate and talk to each other. I imagine a combination of Soundtransit and SoundCloud, with an iPhone app to make recordings and upload them.