I have tried out mBlock over the past two days. This will be a nice way for my Robotics kids to start looking at using the arduino.
mBlock, based on Scratch, provides a block based interface to coding the arduino. It has two different modes. While tethered via usb you can experiment with the blocks starting and stopping any action as you would with Scratch. In arduino mode you can upload your code to the arduino and have it reside on the board without being tethered the way we are with Scratch and the Hummingbird board.
In the picture below I added a button, a servo, a LED and an ultrasonic sensor to the arduino. When I run the code I can activate the LED and the servo based on a switch and sensor value. On another board I tried running a motor with success.