Wikispaces might be useful in several ways. I could post topics about physics or astronomy in the news and have students comment on them. I could ask students to post articles or links to articles that they have found about science in the news. I could post a picture or video from NASA's
APOD and have students comment.
I could post a problem and have students post about how to solve it. I could post review questions or practice quizzes.
Voicethreads could also be used for posting problems or science in the news articles. There are more ways of commenting than in Wikispaces. It might be good for students who have a hard time writing their thoughts to be able to just speak their comments. It would be a type of differentiation for these students. Many of the websites and webtools that we have been exploring can be used for the same purposes, It is just a question of which one would be most
convenient for the specific purpose at hand.