Which pid corresponds to which AppPool?

In troubleshooting IIS 6.0 performance issues, it's helpful to use Application Pools (AppPool) to isolate web sites to their own instance of w3wp.exe . Once you perfmon the w3wp.exe instances, you'll need to know which instance corresponds to which pool. The command you'll need is:

cscript c:\windows\system32\iisapp.vbs