We have 6 desktops running Ubuntu 12.10 in a writing and advanced IT lab. Behind 4 of the Ubuntu desktops are Raspberry Pis. (We have small class sizes - max 4 students per IT or Web Dev class).
The 4 desktops hiding Raspis have HDMI TVs (slow response time for gaming, but fine for productivity) ($99 each at Amazon). In addition, there is an I/O Gear KVM switch for switching the usb keyboard and mouses from desktop to raspi and back. To switch the displays, we use the source button on the remotes that came with the TVs. Each Raspi has a 5-port powered USB hub connected. And the Raspis themselves are powered by HTC chargers.
Each Raspberry Pi is running Raspbian (Debian Wheezy). Each has an 8GB SD card that needs to be upgraded to class 10. Accessibility software is installed on each (noteably writetype). Also installed are xrdp and epoptes-client (lab management software; it’s on each ubuntu box as well). Openssh-server is running on all the machines.
We’re not working with Raspi or Debian derivs exclusively. On xenserver, each student administers a Win7 machine. On a headless virtualbox (Ubuntu) server, each student also administers a Fedora 17 VM.
In addition to linux and Win7 administration, students in Information Systems Management learn VM creation and administration. They also spend the first quarter on hardware (always authentic): e.g., this year they built an xenserver machine. In prior years they’ve built an esxi machine, a multimedia streaming machine to deliver content throughout the school, etc.
Our current unit focuses on batch files in Win7 and administrative scripting in bash and Python (on raspi).
All the machines, including the production desktops, in the lab are administered by students, each of whom can escalate privileges as necessary.