Microsoft has recently released a new version of their MultiPoint Mouse SDK. This technology is designed to allow up to 25 users to simultaneously interact with a single PC each using their own mouse. The stated goal of this technology is to support educational environments and full-class participation.
The 1.5 series of Windows MultiPoint Mouse SDK brings template for Visual Studio 2008, a simplified object model, and support for 64-bit operating systems. The requirements are minimal, just Windows XP SP3, .NET 3.5 SP1, and two or more mice.
A related product is the MultiPoint Server operating system. This terminal-server like product geared for the educational market. Each student gets their own monitor and input devices, but under the covers they are all running on the same physical machine. In addition to monitoring capabilities, this allows administers to install applications once per server instead of once per student workstation.