Have you considered the noise-isolating earphones that fit inside the ear, like Shure or Etymotic? I do not own a pair myself (I am a cheapskate and just bought some Sony inner ear phones, which are not as effective at blocking noise but still make a difference), but many here on Flyertalk are quite happy with them. They are far, far smaller than headphones like Bose and much easier to carry. I would never think of dragging around a giant thing like Bose and am much happier with my inner ear phones.

I would give you more detailed info, but since I don't own any myself all I can do is suggest you do a search for Shure, Etymotic, innear ear phones, etc. (Sorry!) Many threads have been posted on this topic.

Hope you find the info you're looking for!