Helping Your Math and Science Students with their Homework

Recently one of my students told me that he forgot his homework because "his shampoo bottle leaked all over it." Now I've heard some pretty interesting excuses, but that one topped the list! Whether it was true or not, the fact is that our kids are often disregarding their homework.
Why? Some may be deemed "lazy" by some teachers, while others just don't understand. I was one of those students who would often "get it" in class and totally forget it at home. It's frustrating, isn't it?
How can we help our kids do their homework in Math and Science? Perhaps providing a link to a video clip that would help "reteach" or supplement the instruction that took place earlier in the day. Sites like Khan Academy exist to do this.
One of the most recent sites that I have come across is Brightstorm , a free homework help site for Math and Science. The site boasts of providing Math help from Algebra 1 to Calculus and Science help for