add style to list separator, so one could write to userstyle.css:

table.dataplugin_table span.sep {
    display: block;
    font-size: 0px;
}

and have list items listed below each other

--- data/helper.php	2010-02-23 03:00:00.000000000 +0200
+++ data/helper.php	2009-09-10 09:00:02.000000000 +0300
@@ -129,7 +139,7 @@
                     }
             }
         }
-        return join(', ',$outs);
+        return join('<span class="sep">, </span>',$outs);
     }
 
     /**