Here is how-to enable debugging on Vista / IIS7, using an application pool in Integrated Mode.   You can either use Visual Web Developer or Visual Studio 2005.   Thanks Scott Guthrie / Rick Strahl for providing the steps on how-to do this.

• Assume you installed IIS7
• Install Visual Studio 2005 SP1, 
• Enable or install Windows Integrated Authentication.   

How-to turn of built-in web server with VWD or VS 2005

• Turning off built-in debugger: Right click on Solution > Properties (project options) >  Start Options > Use Custom Server

Steve Schofield
Microsoft MVP – IIS