In the long tradition of having hidden features, let us have a list of hidden features in IIS 6.0 / 7.0
Do put one feature per answer. e.g. Integrated Pipeline
Inspired by the question on IIS 6.0 vs 7.0
Also See:
Hidden Features of Linux
Hidden Features of PowerShell
Hidden Features of Oracle Database
Hidden Features of Solaris/OpenSolaris
Hidden Features of SQL Server
