I recently came across a great, free online tool at memorize.com. I wasn't sure what to make of it at first, but I asked around on Twitter and got some great feedback. I tested it out and hope teachers will find some great uses for it in the religion classroom. 
Memorize.com allows you to create study materials for quizzes and tests. Just enter in a term/definition or question/answer. One of the coolest tools is the ability to create a diagram quiz. This is great for visual learners and maps.
I created to short samples, one from Jesus Christ: His Mission and Ministry, the book designed for the second course in the USCCB Curriculum Framework, and a map quiz from our Old Testament textbook.
Here is a quick look around at memorize.com and these two quizzes:
