Hello everybody. I want to get back to you with a quick rundown of how this is going.
We've decided to try a video transcribing and subtitling activity as Leigh Thelmadatter suggested ( https://outreach.wikimedia.org/wiki/Education/Newsletter/April_2015/New_to_W...). We are using the Amara.org platform. I put up a list of videos for subtitling or translating from English; students may volunteer to pick a video or suggest their own (which nobody did as of yet) and transcribe / translate it. They get 30 points for the first minute and 10 for every additional minute they complete.
Videos on the list are mostly what I recently watched on YouTube. I did not include any videos from Commons. Videos on my list that were at least partially subtitled (or translated) by the students include
* http://amara.org/en/videos/pasvCxmxuUQu/info/what-is-out-there-the-story-of-... *http://amara.org/en/videos/GFc5Vo3aPWDY/info/review-papers-please/ * http://amara.org/en/videos/uaCmbPpZlDlI/info/how-to-write-a-great-research-p... * http://amara.org/en/videos/pasvCxmxuUQu/info/what-is-out-there-the-story-of-... *http://amara.org/en/videos/5dbfHRf7dVk9/info/review-gone-home/ * https://www.amara.org/en/videos/4xI2pqoAX8i3/info/make-yourself-happier-usin... *https://www.amara.org/en/videos/5kDUeKxDRhen/info/review-goat-simulator/ * https://www.amara.org/en/videos/iJlXx9cGQufF/info/emma-watsons-un-speech-wha... https://www.amara.org/en/videos/iJlXx9cGQufF/info/emma-watsons-un-speech-what-she-didnt-say-heforshe/# * http://amara.org/en/videos/wtnIGLW8jjHN/info/google-wave-natural-language-pr...
What I did not figure out yet is how to motivate students to do Peer Review. I offered 10 points for reviewing every minute, but students mostly ignored it and did not participate.
Thank you for all your suggestions. I plan to eventually extend this activity to Wikipedia articles too.