Silence, please!

It's ironic, but my workplace is not the better place to work.

I'm a programmer. I don't do any sort of intensive physical handwork; I work with my brain, in fact, my job is thinking; when there is a problem I have to think about a solution, and I need to concentrate to find the most suitable one. And in order to concentrate I need silence, but that's something very unusual at my office (in fact, it's something very unusual at every office).

Because of the noise, many times I end up working with background music, but that only works for me when the task I'm performing at that moment is mostly mechanical, e.g., building a new binary release and uploading it to the versioning system. But when I really have to concentrate I do need silence and turn the music off. As soon as I quit my headphones I start noticing workmates conversations, incoming phone calls, a motorbike at the street, the printer,... the office is full of disrupting noises.

Something has to be done about noise at the office. I'm not claiming for a "noise police" but I'd like to promote a "culture of silence". And I think some little steps can be made in that direction. For example, everyone should silence the mobile phone. Usually, the first thing I do when arriving at the office is to silence my phone and leave it between the screen and the keyboard, that way, if someone phones me the phone screen flickers and I'm the only one who notices it.

Do you have any other little solutions to encourage silence and achieve a better workplace?