I just got my Targus XL backpack from Amazon. The bag is huge. It fits up to a 17″ laptop and has plenty of compartments. I am able to carry the following items:

• HP dv9999us laptop (17″ laptop) and cables
• Apple MacBook Pro (15″ laptop) and cables
• Canon CanoScan LIDE 500F scanner and cables
• Logitech USB mouse
• Targus PA248U laptop cooler
• Western Digital Passport 250GB (portable HDD)
• other little things

I was curious and weighed the back it was about 23.9 lbs. I still have room to spare and if I wanted, I could carry a book or 2. But it was getting way too heavy.