The topic of debugging came of in my talk SharePoint Development for ASP.NET developers earlier this month.  One technique I mentioned is the process of determining the application pool ID using the often used iisapp.vbs file.  I went to demo this on my Windows Sever 2008 virtual machine only to find that this file no longer existed.  After doing a bit of research, I discovered that is because this file was removed and replaced with appcmd.exe (which is a lot more powerful).  Appcmd.exe is located in c:\windows\system32\inetsrv. 

Here is the command to list the worker processes:

appcmd list wps

I found this information on TechNet.  From the article, I also learned you can get this information through the IIS Manager UI if you so chose.  Just click on the server, and look for the Worker Processes icon.