After somebody suggesting that Arduino need BASIC, I discovered this:
http://s4a.cat/ - Scratch for Arduino
It pushes 'firmware' to the Arduino, allowing you to build Scratch designs that will sense and control the pins on an Arduino - the scratch scripts actually run on the PC.
Sure, it doesn't let you develop a standalone board, but it looks to be a pretty slick way for beginners to interact with the physical world (e.g. LEDs, wires, switches) without learning C.
I might build an proximity alarm to demo at Codeclub next week (ultrasonic sensor, servos waving signs , "Danger Will Robinson" audio from the PC.... ).