Nice. I tried to write a quick version of this for my response, but wasn't aware of insert-key-sequence.
Edit: insert-key-sequence doesn't exist on Emacs 22.3.1, is that a more recent addition?
Also, while not crucial, I prefer to add a my-X-mode-hook function and add things to that, rather than adding several lambdas to the mode hook - it's easier to modify them all after binding that way.
Not offhand, but I looked it up and I think what you want is `key-description'. It prints key sequences, so e.g. (key-description "\370") evals to "M-x".
Edit: insert-key-sequence doesn't exist on Emacs 22.3.1, is that a more recent addition?
Also, while not crucial, I prefer to add a my-X-mode-hook function and add things to that, rather than adding several lambdas to the mode hook - it's easier to modify them all after binding that way.