Edit: Okay, I think I've actually found what you need: MSDN has instructions on how to use SvcTraceViewer.exe http://msdn.microsoft.com/en-us/library/ms732023.aspx which would seem to fit the bill.
In your asp.net app, go to trace.axd, you're trace messages will be there. If your asp.net app is at http://bob.com/woot then go to http://bob.com/woot/trace.axd and you'll see your trace messages. There are settings in the web.config you have to set in order to access the trace remotely.
<configuration>
<system.web>
<trace
enabled="true"
requestLimit = "10"
pageOutput="false"
traceMode="SortByTime"
localOnly = "true"
/>
</system.web>
</configuration>