I stumbled upon a really good site for the Math teachers to look through. For those of you who know me, I'm not a Math person by any means, but this interactive site looked helpful and interesting to me.
Math Playground is a site that has tons of great resources. The best part of the site, is that many of the lessons and games they have on their are interactive. This means you can utilize your Smartboard in class. Most kids learn better if they are allowed to get up and interact with the lesson they are learning. These games could be used for review or shortened class periods to reinforce the lessons you have already covered.
I played Alien Angles for a couple minutes and it was interesting. Students need to set the correct angle they give you to allow the Aliens to land their craft safely. Some of the games might not be helpful at all levels, but there are some that could be very helpful to struggling learners as they try to catch up in class.
Interactive Sudoku is a fun game under Logic Puzzles. It forces kids to think of the big picture as they place the numbers in the appropriate boxes.
Word Problems is a bit young for High School, but you may find some parts of it useful for your classes.
Math Videos has a ton of useful video Algebra, Geometry and other useful Math areas.
Take a look at the site and see if there is anything you could use. Give it a try.