How does one "hash" this password? If the user only has to "play" within 80% accuracy, then surely the password is stored in the clear
You don't have to reproduce motions precisely to yield a consistent input…think of it like typing letters on a keyboard…you don't have to hit them squarely in the middle every time to produce the desired letter. You then take the input, hash it with some other data (provided by the software or website) to yield a password of sorts (like passwordmaker.org). Of course, it could also be used to decrypt a private key and sign a transaction.
I just think it would be cool to be able to wave your hands in the air in a certain, repeatable pattern to sign a transaction.