Third Hand is a Visual Studio Add-in that allows you to use to your voice to control Visual Studio. Rather than navigate the toolbars or use the menu, say "Solution Explorer", or "Properties" and those windows will open for you. This keeps your hands on the keyboard, hopefully increasing your efficiency.
The add-in makes use of the System.Speech namespace introducted in .NET 3.0. It should work on any system with SAPI installed and speech recognition enabled.