use strict;
use warnings;

my %hash = (
  foo => 'bar',
  42  => 23,
  hello => 'world',
);

my @interesting_keys = qw(foo hello);
my @values = map { $hash{$_} } @interesting_keys;

my @interesting_values = qw(bar 23);
my %reversed_hash = reverse %hash;
my @keys = map { $reversed_hash{$_} } @interesting_values;
[download]

Update: Made the code conform to strict, after tirwhan's note.

You're missing a my before the @values and @keys arrays.Update: Not any more.

And while I'm nitpicking :-), personally I find it clearer to use a hash slice instead of map:

@values = @hash { @interesting_keys };
@keys   = @reversed_hash { @interesting_values };
[download]

YMMV of course.

All dogma is stupid.

Reversing a hash is cool but dangerous. If the original hash has repeated values, reversing it loses information.

the lowliest monk

But in this case, I assume the hash is reversible, as the original post doesn't mention what to do in conflicts :)