I wanted to mention that you can install Scratch 2.0 offline—it runs as an Adobe Air app. See http://scratch.mit.edu/scratch2download/

The offline editor also lets you import extensions, which means that if you're adventurous, you can hook up Scratch to your NXT, your Arduino, your LEAP Motion, your Sphero, your Kinect, anything. That should be pretty exciting for new coders. A friend of mine's speaking about this at the Scratch conference now-ish.