Alex writes: "Some incredibly generous Germans have set up a mike and speaker inside a huge concrete tank that used to be filled with water for steam trains. Thru the website you send a sample, it gets played out into the tank - and the result sent back to you in stereo! Which is nice of them. I had a go at doing my version of Alvin Lucier "Sitting in a room". This [mp3] is the 5th generation. Pretty sweet!"
It's called Tank-FX.de and it really works - when I tried it, it took about 30 seconds from uploading to getting my file back. It must be cool standing in the tank hearing all the weird noises coming in from all over the world.