Comment Android Browser and Device Lockdown is possible (Score 1) 260
Use SureFox browser (Android version) to allow only certain websites. Access to any unapproved websites are blocked by the browser. There isn't even an address bar. You have to per-configure everything before the users can use the tablet. No need to mess with the network configuration.
http://www.42gears.com/surefox/
Also look at SureLock to allow only SureFox as the allowed application. Users can't access any other applications or System Settings.
http://www.42gears.com/surelock/