Hurrah for white (or brown) noise. If you are in an environment that is full of chat and conversation its great for blocking all that out. You can still hear that people are talking , but you can't understand what they are saying so you can more easily block it out. Wonderful if you are a bit of an introvert and want a little bit of mental isolation in cubeland, or even worse, an open plan office.

The problem with the SimplyNoise site is that the track only lasts 30 seconds or so and then repeats, so every 30 seconds you hear an annoying click. Instead, download Audacity which can generate a brown noise track as long as you want. I have a 30 minute brown noise track as an MP3 which I have on repeat.

Don't even dream about using this to make your one-time pads without rigorous analysis of the data, making really random bits is a lot harder than it seems.

http://en.wikipedia.org/wiki/Colors_of_noise