The only reason you need to explicitly quote the Left Hand Side of the => operator is if the key contains white space*: 
my %hash = ('key 1' => 'value1');

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Off-Topic:
I have to note that PHP also has the arrow operator and it works in the same mannor. However, PHP is "broken" in the sense that you have to quote any keys that are reserved words. For example: 
$hash = array(
   title   => 'Hello World',
   'class' => 'this key has to be explicitly quoted',
);

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Also note that PHP allows trailing commas, but not in a function parameter list. Crazy.

UPDATE: silly /me - you need to quote keys that contain \W (that is, non alpha-numeric). Thanks liz and Anonymous Monk. :)

UPDATE 2: thanks for catching that YuckFoo

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

In reply to Re: regarding hash keys by jeffa
in thread regarding hash keys by jai

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