Well, I can think of two nice mnemonics for "conejo" offhand!

First, and most academic: a "coney" is a rabbit, and they sound similar. Second, if you know "cojones"... well, what are rabbits famous for doing? :D

Oh, and for "palabras", think "palaver" (flattering or congenial words).

Can't help with "keys", though; that's an odd one. *stares it down*