We've just scratched the surface of Moodle so far- it can do a LOT. When you're ready to explore some of the other features, check out the links below.
Wiki- You and your class can work collaboratively to build a basic website, perhaps to use as a repository of collective knowledge gained during the course, or as a side project exploring a certain topic. Now that students can directly upload images and media the Wiki is MUCH more useful.
Blogs- If you'd like a non-public system for students to record thoughts and reflections, the blogs within Moodle can be useful. Get into the Blog system by adding the Blogs Block to your course. Blogs are tied to the user, not the course, but the Blogs Block gives you options for writing and viewing posts related to the course.
Glossary- The class can work collaboratively to create a glossary of terms, with each student adding entries.
Quiz- You can build a bank of quiz questions and use them in a various quizzes.
Lightbox Gallery- You can use this module to create an image gallery. Beware that it is a little clunky to use and has some bugs- not all the editing options work for example. For best results, re-size your images before bringing them in (to no larger than 900 pixels wide).
For the motherlode of information, visit Moodle.org, the official Moodle help & how to site.