Here's an algebra resource that should interest (at least some) boys: Off-Road Algebra is a unit-study that revolves around the world of off-road motorcycle racing. The lessons fit pre-algebra and algebra, or approximately 9th grade.
For each of the 30 lessons, you view a video, then solve a problem. You'll also get printable explanations and solutions to all problems.
Glancing over the problems, they seem to cover a wide array of topics, such as miles per gallon, velocity, slope of ramps, GPS coordinates, decibels, acceleration, turn angles, lap times, and so on.
And it's all free (sponsored by Learning.com and Aha!Math) - so thanks, HotChalk and Learning.com!