Divide the list into two columns (get_posts)

You could do this with the modulo operator.

$posts = get_posts($args);
$html="<ul>";
$limit = 5;
$i = 1;

foreach ($posts as $post) {
    $html .= '<li>' . $post->post_title . '</li>';

    if($i % $limit == 0) {
        $html .= '</ul><ul>';
    }

    $i++;
}

$html .= '</ul>';
echo $html;