This is a great math website for elementary and middle school students. It contains a lot of information along with fun activities, games, worksheets, and quizzes.
This set of applications lets you set up audio drop-boxes so your students can record and turn in their spoken answers. There are also ways to create worksheets for videos and embed them together in a "mash-up" activity. Especially for foreign language teachers, this seems like an awesome assortment of apps!
This website contains flashcards and games to help students improve their math skills interactively. It also contains worksheets that students can print and work on. The website also has the answer sheets so students can check their work. There is also a "homework helper" tab that allows you to input your problem and answer and it will help you figure out if you are correct.