This study site, http://quizlet.com/, is so much fun! Anyone studying for the SAT or ACT should definitely check it out. I've been using it to improve my French vocabulary. Quizlet offers "study sets" for everything under the sun, including standardized tests from AP exams to the LSAT. If you can't find the study set you're looking for, you can create your own! The site provides digital flash cards and a variety of study tools, interactive games and tests that use the concepts or vocab you're learning. When you get a question wrong, Quizlet gives you the correct answer and prompts to you "spell it" before you can proceed.
As you play, you can see other studiers' game scores. For me, the element of low-pressure competition is very motivating. On the home page, you'll find a live map that shows what people are studying around the globe. You're not alone! Study hard and have fun!
The best part: it's free :)