For a somewhat less-expensive option that doesn't look like a Star Wars toy, check out the Kriega pack -
http://www.kriega.com/R25.html
It holds my Powerbook laptop pretty nicely, and doesn't have straps flying in the breeze. It won't protect my computer if I crash hard enough to land on my back, but I might not be too worried about computer damage if I did.
http://www.kriega.com/R25.html
It holds my Powerbook laptop pretty nicely, and doesn't have straps flying in the breeze. It won't protect my computer if I crash hard enough to land on my back, but I might not be too worried about computer damage if I did.