Flex RemoteObject and Server Session State

I've been trying to use mx:RemoteObject to access server session state. I write the following code:

<mx:RemoteObject id="objSession" source="servlet" />

in flex.war web.xml -->

<servlet>
<servlet-name>servlet</servlet-name>
<display-name>Provides access to the current session;
for use with RemoteObject
</display-name>
<servlet-class>flex.bootstrap.BootstrapServlet</servlet-class>
<init-param>
<param-name>servlet.class</param-name>
<param-value>flex.server.j2ee.remote.Session</param-value>
</init-param>
</servlet>

What am I doing wrong? I don't have the flex data server. Do I need the server?
Also, Is there a better way to do this?

--thanks for any help. Bret Mullinix