function stwc_website_link() {
  $data = bp_get_member_profile_data( 'field=Website' );
  if ( $data )
    echo "<span>Website: <a href='{$data}'>{$data}</a></span>";
}
add_action( 'bp_directory_members_item', 'stwc_website_link' );
//Not the best code in the world but should do the job.