You can use jQuery Library for Sharepoint WebService
<script type="text/javascript" src="filelink/jquery-1.4.2.min.js"></script>
<script type="text/javascript" src="filelink/jquery.SPServices-0.5.4.min.js"></script>
<script language="javascript" type="text/javascript">
$(document).ready(function() {
$().SPServices({
operation: "GetListItems",
async: false,
listName: "Announcements",
CAMLViewFields: "<ViewFields><FieldRef Name= Title /></ViewFields>",
completefunc: function (xData, Status) {
$(xData.responseXML).find("[nodeName= z:row ]").each(function() {
var liHtml = "<li>" + $(this).attr("ows_Title") + "</li>";
$("#tasksUL").append(liHtml);
});
}
});
});
</script>
<ul id="tasksUL"/>