roboticus has good points. I would add the following only as an additional consideration:

use strict;
use warnings;

main();

# always have an exit from a script, it will save you grief!
exit;

sub main {

    ... # do some really cool stuff here

    # always have a known return value, just falling off the end WILL 
+bite
    # bite you someday.
    return;
}

__END__
[download]

The use of exit and __END__ can prevent unexpected additions to your script for one reason or another. It is also handy to have all your POD (you do document your code, right?) after the __END__ statement.