Hitachi Maxell has released a pair of noise-canceling headphones that work a bit differently from their cousins. The HP-NC20 headphones don’t require separate power. They simply connect to iPods via the dock connector. They manage about 20dB of noise reduction via their "Active Noise Rejection" system. They also manage to reduce your battery life by as much as 50%. The headphones will also only work with 4th gen or later iPods and iPod touches. They do not work with the iPhone. They are available now for about $80.