I recently got my hands on Lego Mindstorms, which coincides very nicely with the release of the Microsoft Robotics Studio September 2006 CTP. According to the website: "The Microsoft Robotics Studio is a Windows-based environment for academic, hobbyist and commercial developers to easily create robotics applications across a wide variety of hardware. Key features and benefits of the Microsoft Robotics Studio environment include: end-to-end Robotics Development Platform , lightweight services-oriented runtime, and a scalable and extensible platform." The features that caught my eye include the new visual programming language (VPL), which provides a great developer experience (like the LabView software that ships with the Lego set). The new CTP includes a tutorial to control robots using Windows Live Messenger, simulation support and improvements all around. You can check out the studio at the following link: http://msdn.microsoft.com/robotics/