While a little off of the main topic, I swear by headphones during work hours; I listen to much more music during work than I do otherwise. I've recommended them to people in similar situations to yours - it not only gives you a way to block out some of those distractions around you, but tends to stop people from simply chatting with you for no reason.

Given the move to cubicles and open concept offices, I'm finding headphone use is very common and is a generally accepted practice in most offices (I can't think of any exceptions off the top of my head). This is one way the individual office worker can control their work environment irrespective of the situation they are put in.

And if you don't like listening to music, I know other people who have said good things about the use of noise cancelling headphones instead.