I forgot to mention another bonus of the hot-potatoes suite of software. It is so user friendly and understandable, that the pupils can use it to make their own quizzes and tests.
Gather a few animated GIF files, mp3s or even .swf flash animations, where they can browse through them and embed them in their own hot-pot teaching materials. The response when they see their own work loaded up into the school system is very positive. They also tend to put a lot more "credability" on to the offerings of peers in comparison to teachers' materials.
If they produce a test in their own PC directory, you can simply zip the finished hotpot file and associated graphics into an archive using winzip or similar. You can upload into Moodle and "unzip" in-situ on the server.
I think this aspect is really one of the fundamental principles behind Moodle anyhow. If you want any example files, please let me know.