A long time ago, I came across a handy little utility that, if turned on, would append the contents of Session and Application to the end of each page.
I'm trying to maintain a very old VS 2003 application and something like this would really be helpful as the app makes extensive use of globals via the Session.
You have to enable Tracing:
<configuration>
<system.web>
<trace enabled="true" requestLimit="40" pageOutput="true" />
</system.web>
</configuration>
http://msdn.microsoft.com/en-us/library/bb386420.aspx
If you want a specific page (not all pages):
<%@ Page [...] Trace="true" %>