The Quizlet Blog is a good source, not just for using Quizlet, but for lesson plan ideas like this one for Black History Month -- or any time of the year that race might come up as a topic. And when doesn't it?
...Class members were invited to start their own blogs (which I then linked and followed by means of a Feevy students in turn chose to embed into their blog templates) and weekly post their reflections on assigned readings.... fostering individual expression ... the weekly assignment also involved posting a comment on at least an entry made by a partner...