On a recent long plane flight I used a pair of noise cancelling headphones and was quite impressed.
Has anyone used this type of headphone for location sound recording.. if so have you discovered any problems?
Noise-cancellation headphones can have very unpredictable results. Its one thing to use them to listen to music in an airplane. If, on the other hand, you were trying to record dialogue on that airplane, the headphones would likely play havoc with what you're actually hearing.
If conventional monitoring headphones (eg. Sony MDR-7506) aren't giving you enough isolation, check out the Remote Audio HN-7506. With them, you know exactly what you're hearing: no fancy phase cancellation or realtime audio processing, just big-honkin isolation baffles. I picked up a pair to record heavy machinery, and they've since become my `phones of choice for field recording.