I have been searching for a way to quiz or test students electronically online. There is a free site called Hosted Test that allows you to create exams and quizzes so that responses are sent to you. It also grades students on each question immediately if its multiple choice. It is not the most user friendly program in the world, but if you are interested in making small quizzes it is easy enough.

Go to www.hostedtest.com and click "TRY IT." Follow the instructions and begin making quizzes!