If I really need to block out everything I use http://simplynoise.com/ and turn the brownian noise all the way up and turn on oscillation. It both calms me and lets me focus on what I need to do for extended periods.
I've tried downloading the loopable brown noise file, but when I put it on a loop in quicktime there's a break at the end of the loop which is annoying.
Anyone knows how to make a seamless loop?
edit: I've tried it in iTunes and the break isn't quite as annoying (though still there). You can make it a bit more "full" by playing the website (oscillating) and the loop file at the same time.
Also this seems like a perfect excuse to program a solution, if you are so inclined. I've used supercolider in the past and it was easy to pick up quickly. http://www.audiosynth.com/
I've found that - on a Mac - you can simply make a Dashboard widget with it. You have to go in the options and uncheck "Play audio only in dashboard", though.
