Block the Distractions with White Noise
If you're trying to work in a noisy environment, some white noise might help block out the distracting sounds. I work from home, with an office that faces the street. It's usually quiet, but when the kids are out of school for the summer, things get a bit noisy sometimes.
If I'm trying to concentrate, I put on my headset and go to http://www.simplynoise.com/ for some white noise. There's a slider that let's me adjust the volume, and that's it. Nothing to fiddle with, no choice of sounds, just simple noise, as promised.
After a couple of minutes I forget that I have the headset on, the outside sounds fade away, and I can focus on my work again.