PowerShell PowerTab
Lately I found myself using the Microsoft PowerShell more often. But I am frequently missing intellisense. Especially when I want to access framework classes which I do not use that often. Luckily there is a very good extension script maintained by the powershell guy called PowerTab. It adds all the intellisense mumbo jumbo to the powershell and make it even more usefull then it already is.
Go to the PowerTab page