Yes, get a backpack. Not only will 2 strap spread out the load but the notebooks backpacks look like a student backpack (especially if you choose one of the plain black ones like the Targus Pulse) so it is less likely to be targeted (especially if taking it through airport security).
More expensive models have more ballistic nylon on the straps and back of the backpack so try some out.
See www.targus.com -- Fry's Electronics stocks some of them and has sales on certain models all the time.
Samsonite sells student backpacks also with the notebook sleeve and ballistic nylon.
The Targus models that state the will hold a 15" notebook will fit the 15.4" widescreen of the Dell 8600 as it drops in sideways (I have a 15.4" Compaq X1360US and I have a Targus Pulse). This model is all black and I only paid 19.99 after rebates on sale at Fry's but it has less padding then the Targus Matrix for example -- so I would recommend moving up in the model line a bit if you will be carrying it everyday.
Note that Targus also sells the premium Port backpacks which have the maximum notebook protection (air filled bumpers) but these have much more robust handles outside and signal a notebook is inside).
I'm looking for a case for my new Inspiron 8600. I'll be carrying it around campus. What should I consider when buying one? Should I go with a backpack? I'm worried about the stress on my back. If I get a handheld case of some sort, what's the best one to get, with price not being a factor, and what's the best to get at the lowest price?

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