Now that Youtube has linking directly to specific times in a video all we need now is a "play until" variable and someone can put together a Re-CAPTCHA-like product for transcribing Youtube videos.
After our son was born we started watching TV with closed captioning enabled for when the heater starts blowing. Otherwise we were just blasting the TV to hear above the noise. What I discovered is closed captioning (looking at you CaptionMax) sucks. There's no reason it needs to suck so much for deaf people on the web.