I'm convinced I could operate some kind of (very sensitive) input device while lucid dreaming. I can touch type well so I'm thinking of making "keyboard gloves" or something to communicate from the other side. Though I should have a look - I can probably already order them on Kickstarter.
There's a guy setting up to experiment with morse code via eyeblinks: http://lsdbase.org/ I don't think he's quite got the hardware all done yet.
It's probably the best plan. It has been scientifically demonstrated that eye movements are under something like conscious control (for the relevant value of "conscious") during dreaming, as shown by the famous recording of someone's eye movements going back and forth very clearly, while the subject reporting watching a tennis match. There's nothing else you can count on being able to move; I'm not sure what typing you expect to occur in the real world no matter how strenuously you type in your dream.
