I'm an eLearning Specialist at the University of Alberta now, but little is it known that I worked with Edmonton Public Schools for a couple of years. In that time, I taught English Language Arts and Math to elementary students. One of the coolest projects we had was making posts on a class Google Site together. After learning and practicing key concepts, students had the opportunity to choose a topic that they felt confident in, and they created Google Slide presentations with the goal of teaching the new students for next year the concepts they had learned. These slides were loaded into our class Google Site and the materials were used for the next year, with those students making modifications or creating new slides to add to the collection.
I wish I could say this site still exists. Alas, when I left Edmonton Public, my Google Drive was laid to rest. The materials are in a better place now. Luckily, the students will still have the presentations they made and can upload it to their MyBlueprint portfolio for their K-12 experience.
This is very similar to Domain of One's Own, and the ChemWiki Rajiv spoke to in his presentation. I would highly recommend instructors take these ideas into practice and have students make the OER with you, especially in an accessible, open database that can be viewed by thousands for years to come! That way OER gets out there, you delegate some of the load to the learners, and they have more meaningful learning experiences in your course.