This should display your categories, in column lists of any specified amount. I've told it to display 3 columns at bottom. If you want it to also link to them, let me know.
Code:
function columnize_categories ( $columns = 5 ) {
$wp_categories = get_categories( array( 'hide_empty' => 0 ) );
$categories = array();
$per = ceil( count( $wp_categories ) / $columns );
$i = 0;
while ( $cats = array_splice( $wp_categories, 0, $per ) )
{
$categories[$i++] = $cats;
}
$output = '';
foreach ( $categories as $list )
{
$output .= '<ul>';
foreach ( $list as $item )
{
$output .= sprintf( '<li>%s</li>', $item->name );
}
$output .= '</ul>';
}
return $output;
}
echo columnize_categories(3);