Web 2.0 Flash cards

I just read an article on TechLearning.com by Jenn Farr on creating Web 2.0 flashcards (http://www.techlearning.com/article/16896) and thought I'd post the three online flash card sites that I checked out that I found easy to use. 

All of them also have a huge number of already created flash cards for students to use.

http://www.studystack.com/

http://flashcarddb.com/

http://www.flashcardexchange.com/

Try them out for yourselves and let students know about them. Besides looking up already created flash card sets, students can create their own for studying.