f13.net

I wasn't sure where to put this but anyway, I need a new backpack/bag of some kind.

I'm a grad student so I have a laptop and lots of books and papers on me at all times.  My current bag just cannot crammed full of things.  I use a wheelchair to get around so weight is not an issue.
I found this at the bookstore on campus: http://www.ogio.com/product/view/25/Street-City-Corp (http://www.ogio.com/product/view/25/Street-City-Corp)
The only problem is is that there aren't enough straps to keep it secure to the chair so things would swing about, etc. 
Ideas/suggestions would be appreciated.

The top item at this site (http://www.wheelchairgear.com/accessories.html) seems like it may do the trick. Not sure if you'll dig the color scheme, but I found that in about two minutes by Googling "backpacks for wheelchairs." "Wheelchair backpacks" would also, presumably, turn up some good stuff.

If you want something less Jansport-looking, you could always hit up an Army-Navy surplus store. Some of the bags there may meet your needs -- big, but with lots of various attach points for strapping down.

I've never been a heavy laptop user, but I always preferred a second bag for when I did carry one.  The extra padding didn't make me worry about things in the first bag crushing it.  Plus I'm not really the strongest person out there, so it let me distribute the weight better.  Is distribution an issue, even if weight isn't?  Does it all need to go on the back, or can you have something slung underneath?

Yeah, it needs to go on the back.  There's no where else to put stuff.  I can't put things on the side that hang because they would most likely hit the switches that put me into neutral while driving.
Here's the base model of my chair: http://www.pridemobility.com/quantum/powerbases/q6series/q600.asp (http://www.pridemobility.com/quantum/powerbases/q6series/q600.asp) My version doesn't have handles in the back and a fixed headrest more like a car seat.
The problem with a second bag is that one bag would have to come off in order to access the other one.  It would be a hassle for my friends and a pain when I'm alone.

I have had one of these http://www.saddlebackleather.com/categories/79-Briefcases/products/1655-Leather-Briefcase-Chestnut (http://www.saddlebackleather.com/categories/79-Briefcases/products/1655-Leather-Briefcase-Chestnut) for a few years now.  Best laptop bag I have ever owned bar none and it just keeps getting better with age.  

With all the straps and different ways to wear it I am sure it would fit on you or your chair in some way, shape or form.

I was just coming here to link Saddleback. D'oh.