Yesterday I found a very useful article on MSDN about Enabling Application-Level Tracing http://msdn.microsoft.com/en-us/library/1y89ed7z(VS.85).aspx
<configuration>
<system.web>
<trace enabled="true" requestLimit="40" localOnly="false"/>
</system.web>
</configuration>
So I would to ask if there are other useful config settings that you recommend learning about?