The interface is very nice. The site runs kinda slow, and the lessons require the Real Audio plug-in. The subjects run from Arithmetic to Calculus and Statistics. This book helps with fractions, cancelling units, and word problems. The presentation is non-standard, but his different approach can be very helpful.
Cost is minimal.
They also have quizzes, lists of formulas, and a message board for asking questions. Math League has some nice lessons on introductory stuff like negatives, fractions, and percents, along with worked examples. This algebra program will do its best to turn you into one. You have to really think about what you're doing. If you have lots of algebra to go, the ninety- five dollars for the full program may be a bargain, compared to paying a tutor.