I'm a gal who carries way too much junk around with me, but am trying to change my ways. I used to have terrible shoulder pain due to heavy purses, so about 10 years ago I changed over to a backpack and it is much better. I have a bad back, but if I keep my backpack to a decent weight, it doesn't bother me.
I have used a great variety of backpacks over the years...cutsey fartsy colored ones that are pretty but don't have much organization, well organized backpacks that were ugly, gorgeous leather ones in various colors to match the seasons...but I always seem to come back to the black Targus backpacks. They are well made and organized.
When I bought my iPad I was also in need of a new backpack. I wanted something that was organized such that I could keep my iPad/cords/etc. in one compartment, my wallet and other everyday items in another, my cell phones and glasses in another, my car keys in a small separate easy access compartment, blah blah blah. The Targus Checkpoint-Friendly Air Traveler Backpack for Laptops, has been fabulous. The backpack has really nice padded adjustable straps, a leather padded handle and great zippers. It also has a section you can unzip and the backpack lays open in 2 sections for easy airport scanning (although I haven't been through an airport with it yet...that is the advertisement).
Being a hoarder by default, I am tempted to buy another one of these to have as a backup.
[ame=http://www.amazon.com/gp/product/B001OC5JKY]Amazon.com: Targus Checkpoint-Friendly Air Traveler Backpack for 16 Inch Laptops TBB012US (Black): Electronics[/ame]