My screencast skills aren't perfect yet, but getting there. I've now learned how 'call outs' work. Some of the timing is still slightly off and the screencast ends quite abruptly. Aside from that, the basic point of the screencast comes across well enough. Have a look (6:22 mins):
The text right at the end, which disappears as soon as you see it, says: "That's all folks. Have fun with Groovy! Clearly it makes code generation a piece of cake, not just for files, but even for complete source structures!"
Go here to download the screencast for off-line viewing.
The basic principles outlined above have several implications that I don't I go into in the screencast, but will do so next time. However, I'm sure there's more than enough in there to give anyone a couple of interesting ideas.