I can't think of any good reason why you would want that. Perhaps you could explain what you are trying to achieve and we can make suggestions as to the best way to go about it?
incidently, Using an array as a hash key will result in a key that is the number of elements in the array. ie:
my @a=(3,4,5);
my %h;
$h{@a}='fred';
print keys %h;
will print 3
-pete
"Worry is like a rocking chair. It gives you something to do, but it doesn't get you anywhere."