Comment Sun Ray for classrooms, labs with PCs (Score 0) 411
Sun Rays are a nice, lightweight solution perfect for an in classroom workstation. They do have great performance and I've seen them do some pretty heavy loads. (http://www.sun.com/software/index.jsp?cat=Desktop&subcat=Sun%20Ray%20Clients&tab=3)
For more intense applications, maybe a lab with windows PCs would be good. That way you can expose students to both Linux and Windows, as well as applications such as Photoshop, etc...