When I was in Vancouver, I bought a pair of Panasonic RP-HC500 noise canceling headphones. I’m doing a lot of traveling this fall, and my old headphones had pretty much died. A while back I’d read a group review of noise canceling headphones by David Pogue (here’s some related video), and was pleased to read that Bose no longer had the market cornered.
Wikipedia explains how noise canceling headphones work:
Noise-cancelling headphones reduce unwanted ambient sounds (i.e., acoustic noise) by means of active noise control. Essentially, this involves using a microphone, placed near the ear, and electronic circuitry which generates an “antinoise” sound wave with the opposite polarity of the sound wave arriving at the microphone.
I paid CAN $200 plus GST for mine, and was very happy with them. The earcups are soft, pliable and very comfortable. The whole headset is very light, and fits snugly around my enormous head. There’s even a convenient carrying case which can hold my iPod as well.
The actual noise reduction was pretty extraordinary–it really improved the experience of listening to music or audio books on my plane ride home. I no longer had to crank the volume up to 11 to compensate for the omnipresent background noise of the plane.
I brought them home to Malta, happy with my new purchase. A week later, for no particular reason (there was no, uh, trauma or anything), when I switched on the noise canceling functionality, the right earcup started generating this whistling, wind sound. It’s like the headphones are ‘hearing’ background noise that isn’t there, and trying to cancel it.
This is an extraordinary pain in the ass, as it’s kind of tricky for me to return them to the Best Buy on Cambie Street from rural Gozo. I guess I’m going to have to box them up and ship them home to some kind relative who will exchange them, and then send them back to me. Oy.
DarrenBarefoot.com 
I picked up a pair of noise cancelling Sony headphones over Boxing Day – on sale, of course. They are easily the best purchase I made this year.
I do a lot of traveling myself, and find that there is no substitute for clear, uninterrupted audio. I dare say I’d sooner give up my mp3 player on a long trip than my noise go back to regular old headphones (that is, of course, assuming I could use a CD player instead).
Watch out for the Maltese postal police when you get the headphones sent back to you. We had a faulty computer battery once in France and had someone return it for us to the Vancouver store where it was purchased. When the new one was sent, we were told we had to pay 200 francs ($50 Can) to the post man in order to cover customs charges. No amount of explaining could convince the postal service of the injustice of this transaction and we were left with no option but to pay.
I have RCA HPNC300 headphones, I don’t know if they have all the noise-cancelling mojo of higher-end models, but they work well enough that I can listen to audiobooks on the plane. They fold up quite compactly. C$70 from The Source
http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=NoiseCancellingHeadphones&product=3319644
If I had higher-end models I’d worry about forgetting them on the plane.
Have you had a headphone-returning volunteer yet?