There are other significant public information projects running along side Wikipedia. Wikibooks for example, strives to create free and open textbooks. Consider replacing your essay assignment with writing a chapter to a Wikibook. Take your expensive textbook, devise an improved table of chapters, and ask participants to select a chapter as their assignment. Watch the free and open textbook emerge, and each year ask the new participants to expand or improve on the previous year's efforts. Printing a book out of Wikibooks via PediaPress is especially rewarding.
