A package is just a namespace identified by a string.

package Test::One;

sub hello{
    my $var = shift;
    print "Hello: $var\n";
}

1;

package Test::Two;

sub hello{
    my $var = shift;
    print "Hello: $var\n";
}

1;

package main;

use strict;
use warnings;
use Data::Dumper;

my @pkgs = qw( One Two );

foreach my $pkg ( @pkgs ) {
    "Test::$pkg"->hello();
}
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This is one step toward full-fledged classes and objects, which may be a better solution in the longrun: perlobj.

If you can't plan on passing the package name as the first parameter (which is what the Class->method() notation does), then you have to construct the fully qualified sub name, which means symbolic references and some ugly syntax:

foreach my $pkg ( @pkgs ) {
    no strict 'refs';
    &{'Test::' . $pkg . '::hello'}($pkg);
}
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Update: Good job on figuring out the symbolic ref syntax on your own. Looks like we both came up with the same.