Noise canceling headphones

I had a set noise canceling headphones (Creative HN 505) and mainly used them at my workplace to drown the hum of computers. Recently I took them during a flight and then realized their true value - the experience was amazing. I know they are not as good as expensive noise canceling headphones from, say, Bose or Sony. In fact, the cheapest Bose headphones cost 20 times what I paid for my creative headphones. Anyway, all the engine noise was gone and it was as if I was travelling in a quiet car. The noise cancellation works even if you turn off music from your ipod.

Today I saw a Kensington product that looks just like the ones I have. And Creative apparently has stopped making the ones I have. Maybe they sold their technology to Kensington.