[butter]

this is pretty ghetto, but i have a pair of skull candys (awesome in ear headphones, if you dunno what they are) and then i put a pair of shooting headphones over them, like that you use when you shoot a gun to avoid ear damage.

all in all its about 30 bucks: 15-20 for the skull candies, and 10 or so for the shooting headphones.
not the most professional isolation headphones, but they work well enough for me.