Normally when you mention Wikipedia to a group of academics, there is at least one who will react, bemoaning students who cite articles from it in lieu of peer-reviewed journal content. Now I have a lot of sympathy with this view, especially as it is usually put forward by people who are passionate about their discipline and scholarship, and we need more of those! I can, however, see how wikis can be used to advance learning.
One such example landed in my pigeonhole recently – a series of case studies from wikimedia looking at how universities are teaching with Wikipedia. You can see it for yourself at http://education.wikimedia.org/casestudies.They provide some great examples: language students translating technical pages into the language they are studying (or from the language they are studying into another; students finding articles that needed updating/correcting and amending the content, with full citations; creating wikipedia pages to support particular conservation projects in a protected area; creating and uploading information videos; A common feature of these case studies is the value students found in these activities – authenticity, great feedback from people beyond their institution and pride in adding to collective knowledge.
If you want to know more, there is a conference planned in Leicester on the 5th and 6th of September – see http://bit.ly/eduwiki