I've used a technique like the following.
Mind you I only have 3-5 copies running each
taking between 1 and 3 hours under cron.

#!perl

if (<some parameter not set>) {
    <set up environment etc>
    foreach (@somesortoflist) {
        system(<thisscript><withparameter><&>);
    }
    exit;
}

<remainder of script>
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