Math - to Curriculum or NOT to Curriculum

My son loves math. He's got a lot of talent for math, and frankly I think schools and big textbooks hold him back. I don't really feel confident teaching Algebra, even though I think I remember all the important basics and could always brush up from resources online. However, I'm very confident that my son can almost teach himself Algebra with the right tools and materials.

So I considered getting a correspondence course or online curriculum. Then I found what I think will be the RIGHT thing for my son. A good book, just as a backup plan and for additional examples and explanations, and Khan Academy. Khan Academy is an amazing website written by a person with programming and extensive math experience -- but all the lessons are videos and there's a built-in drill for math problems. When you have 10 problems correct, you can move on to the next level. I cleared some 20 or 30 lessons, earned badges and points, and I think that it has a good mix of real learning when you need it (the videos) juxtaposed with real practice (the drills) for the concepts that either you already know or that you've just learned. When I was done, I invited my son to take a turn at Khan Academy, and he spent almost an hour -- outside of homework -- playing with the math problems, earning badges and points, before going back to playing in his room. :)
I'm impressed. I haven't gotten to any of the challenge levels yet. But I like it. It works with school, homeschool, or as a classroom tool (see this Khan Academy video from TED.com for how to use it in the classroom). Khan Academy is a non-profit, it's free, there's also a few non-math classes (notably Biology, Chemistry, Organic Chemistry), and the math classes are completed to the college level already.
For the math text book, I've found Algebra , Geometry, and practical math/math appreciation books by Harold R. Jacobs. I read the reviews and fell in love. I haven't ordered them yet, but it sounds perfect. Now I need a school budget! ;)