If you are lucky enough to have a few extra computers in your classroom, you may want to use www.vocabulary.com. Your students are given the challenge of answering a variety of multiple choice questions about vocabulary. The questions appear on a note card, giving it a classroom feel. The site has built a database of over 40,000 words and you have options for narrowing your choices down or getting clues. As you compete, you can accumulate points, making it a competition.