[Demented]

Buy a specifically designed laptop backpack. Targus makes some awesome ones. I got this one and I couldn't be happier. I don't go to college or anything, but there is a nice padded section for the laptop, and plenty of other compartments for anything else you may need.

It's roomy, strong, and nicely adjustable. You can also probably find them a bit cheaper at http://www.walmart.com.

That's what I did!