Go To Quiz allows users to create free online polls, quizzes and tests.  My favorite feature, however, is the ability to create multi-answer quizzes--for example, which Harry Potter character are you?  This turned out to be a big hit with my students, many of which create Time Machine-inspired quizzes for quiz-takers to find out if they are Morlocks or Eloi.  The only drawback is that, because the service is free, there are a lot of ads that pop up on their website.  I also hope that, in the future, they offer an embed code so that quizzes can be directly embedded into websites.  Still, creating a quiz is a creative alternative book project, and the price (did I mention that it's free?) can't be beat!  

Classmarker allows the user to create online tests and quizzes.  Several formats are available (multiple choice, multiple response, true/false, correct punctuation, etc.) and quizzes are graded instantly and saved for the teacher to retrieve.  Students can immediately get their test results and view the questions that they missed.  Tests can be timed, and settings include options to randomize the order of both the questions and the answer options, so no two tests are exactly the same.  Tests can also be printed for students who prefer a hard copy.

One of my amazing, tech-savvy coworkers presented a workshop about Quizlet at a district in-service last spring, but I did not take the time to try it for myself until recently.  This website is a great tool; I could see it being priceless for RtI and Special Education students who need accommodations, as well as any student who wants to know how to better prepare for tests and quizzes.  Quizlet allows you to create your own flashcards (which I have used Flash Card Machine to do before).  Where Quizlet surpasses other online flash card generators is in its ability to take the flash cards that you create and turn them into practice quizzes and games.  It also offers the option to print flash cards.  Once the teacher has created a set, he or she can supply students with a URL for direct access; or, you can have students collaborate to create their own cards.

Note: Apparently, Flash Card Machine has added a lot of new features, including printing options, quizzes, and an ipod app.