Quizlet - Quizlet allows you to review and create flashcards for a variety of subjects, such as math and reading.
Kids Flashcards - Kids Flashcards offers free printable flashcards for kids, parents, and ESL teachers of preschool, kindergarten, primary and secondary education. 1300+ picture card are available for learning English, French, Spanish, German, Chinese and other langs.
Flashcard Machine - Flashcard Machine is a free service for creating interactive web-based study flashcards that can be...
PrepFlash - Automatic flashcard generator
Anki - Anki is a program which makes remembering things easy. Because it's a lot more efficient than traditional study methods, you can either greatly decrease your time spent studying, or greatly increase the amount you learn.
Cram - Cram is an app for Android, Windows and Apple devices that allows you to search for flashcards in a range of topics to study for an upcoming test or to learn new information. Read more about Cram.