[Jvince]

Phillips sells a set of noise canceling ear buds at Wal Mart for $20. They also have various soft rubber adapters that will fit any size ear pretty well. I've always hated ear buds with a passion because they just hurt after wearing them for more than 5 minutes. I've worn these for hours on flights with no problems. There's also a nice little inline boost option for increasing the bass and overall volume. You need a AA battery or two?) for these though.

*edit* these are not true "noise canceling" technology, rather "ear plug" type buds that just block out 75% or so of the ambient noise. They still work great and you can't beat the price.