site by Houghton Mifflin is a great one even if you use another resource for Spelling and Vocabulary. Students can choose their grade level ranging from 1st-6th grades. There are various activities for students to participate in to review spelling, proof-reading, and vocabulary.
The activities use Flash and allow students to play online. Activities include a crossword game, word find, word builder, word sort, proofreading, web tales, and more.
Students choose their grade level then select a unit for most activities. There are a ton to choose from so your students can visit this site often and still have new information to study and review!
I would add this bookmark to your site or student laptops/computers and also send it home to inform parents of a great site to help their child review spelling and vocabulary. Your students will have fun and won't even realize how much they are learning! :)