Yeah, well that would be one way of handling it, but unfortunately the real world has terrible issues with not impeding my progress on that front. Not that I'm anti-learning, at all, but - personally - I'm fighting a losing battle against learning German, Swiss-German and Swiss-German Sign-language whilst also being a walking-talking-english-lesson :D
Taking the slow way, with dictionary in hand, is as you point out, an exercise in frustration (especially if the talker/signer is 6 years old).
Yes, I share your dream of something google-glass-like that can add subtitles. There are people working on this (mostly in the UAE, if memory serves). Interesting times ahead - hopefully I won't have to wait long, otherwise I'll have to do it myself and that really would take a while ;)
The dream for me is something like Google Glass with an app that can subtitle spoken, written, and signed language.
> Because people with 20/20 vision just need a sign language dictionary handy and some patience.
I would think a LOT of patience... the easiest way at that point would just to have the other person fingerspell or write what they're saying; if you're watching something where that's not possible, then the dictionary will just be an exercise in frustration.