Not sure if this is worthy of production code use yet as I'm still playing with it. It might never be. I offer it for consideration anyway.

package myswitch;
require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw(switch);
use carp;

sub switch ($%) {
    my ( $expr, $cases ) = @_;
    my $default = $cases->{default}
        and delete $cases->{default}
        if exists $cases->{default};

    my $selector = eval $expr;
    carp $@ if $@;

    for (keys %{$cases} ) {
        $cases->{$_}() and return if eval $_ eq $selector;
    }
    $default->();
}

1;

=pod
Name:
      (Currently) MySwitch.pm
Purpose:
    To provide a simulated switch statement for Perl.

Features:
    Arbitrary selector and case expression.
    It uses nothing but standard Perl so conflicts with other modules 
+should be minimal.

Caveats:
    Testing so far is minimal.
    It captures the symantics of the switch statement, but the syntax 
+is slightly odd
    --but maybe as its Perl that doesn't matter too much.
    If only prototypes were more consistant, specifically if (&) did t
+he same thing when
    it was the second element of the prototype as it does when the fir
+st a much nicer
    syntax could be achieved.
    There is no fall-thru of cases as with the C equivalent (not a bad
+ thing in my book!)
    I make no claims for efficiency as the cases are evaluated in hash
+ order.
    If multiple case expressions evaluate to the same value and match 
+the selector expression
    the case executed is the first discovered in hash key order (Ie. b
+asically random) but it
    should be consistant.

Author: BrowserUk c/o PerlMonks.com
        Copyright 2002, BrowserUk at PerlMonks.com
        Its free and without warrenty of any kind.
        Use it as you will at your own risk.

=cut
[download]

Short, far-from-comprehensive test program.

#! perl -sw
use strict;
use MySwitch;

switch 4/2 => {                            # Abitrary expression for s
+elector.
    1 => sub {
        print 'Expression equals 1'.$/;
    },                                     # NOTE: comma not semicolon
+.

    length 'xx' => sub {                # Arbitrary expression for eac
+h case.
        print 'Expression equals 2'.$/;
    },

    3 => sub {
        print 'Expression equals 3'.$/;
    },

    default => sub {                    # default case (if supplied) u
+sed if no match.
        print 'Expression failed to match any given case'.$/;
    },
};
__END__
# Output
C:\test>switchtest
Expression equals 2

C:\test>
[download]