Here's a slightly more verbose version of the same thing:

#!/usr/bin/perl -w
use strict;
package foo; 
sub new{
my $m = {}; 
bless $m; 
return $m;} 

package bar;
sub new{
 my $b = {};
 bless $b;
 return $b;}

sub corny {
    return 'sparky';
}

package main; 
my $s = foo->new(); 
my $r = bar->new();
$s->{'spark'} = \&bar::corny;
print $s->{'spark'}();
1;
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This essentially calls a method out of a different package. I added the class stuff as window dressing. If you are looking to call and actual method from an instantiated object, just call a function and use a reference to the object as a parameter (called delegation in certain circles) to call the function. Lastly, use inheritance. If these things don't help, I am not sure what you are attempting to accomplish.

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