Zmacs help with key?

Has anyone got a hack for Zmacs that works like FSF Emacs's C-h k
command?  That provides help for a particular key, which actually
looks up the command that the key is bound to and displays the help
for that command.

I suppose I could hack this myself but I figured that someone else
might have done it already.  It's particularly useful for discovering
what the command is that you just did accidentally.  Or for hunting
or unbound keys.  Or just exploring the keybinding space in general.

'james

-- 
James A. Crippen <[email protected]> ,-./-.  61.2204N, -149.8964W 
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