I use a North Face "Borealis" backpack. It has an internal slot that suspends the computer a couple of inches above the bottom of the bag. Setting the bag down does not jar the computer. It is incognito, as it looks no different than a typical backpack. Has a second section with dividers for accessories and deep well that lets the power supply and any heavy tools rest at the bottom of the bag...better balance.

There are adjustment straps to snug up the bag when empty. Also a chest harness and a lumbar belt for when you go hiking or really have to hoof it to make the next flight (or next train). The back is padded/insulated for comfort and also to cushion the computer when you shove the pack under an airline seat.

Opening at the top allows you to pass a drinking tube or cord for headphones. There is a small zippered compartment above the notebook sleeve. I use it to keep my passport, spare library card, and some cash. Came in handy more than once.

They still make this model (MSRP $85.00). Mine is a couple of years old. I got it in red with silver reflective piping. eBags.com had a great deal for far less (usually last season's colors).

I currently use it daily to carry my 9+ pound 17" notebook, mouse, iPod, external drive, power supply, etc. Before that, I carried a 14.1" tablet PC with tons of room to spare...barely noticed there was a computer in the bag.

Very low-key when you use public transportation. Also good to have the straps when you have kids...gotta carry the baby, baby bag, drag the other kid. No free hands to carry an attache or roll-along. Made several trips with this. I liked that I could wipe off the rain or snow without staining the bag (like many black/grey nylon computer cases).

Pack doubles for recreational use. Trips to the beach. Hiking.

I do not think anybody makes better laptop cases than Spire. I use a Volt which is one of their smallest. But I love it because it EASILY fits under the seat in front of you on the airplane. Mine is 5 or so years on and has taken a ton of abuse and still looks great. They have EXTREMELY friendly people working there. I just can't say enough good things about them.

They are all two piece. They have an internal boot that fits snug around your laptop and then a pocket in which that boot goes into the backpack. There is so much padding that I've been quite abusive to my laptops(not really mine my companies) and have never broken one yet.

The type of bag that you get for your laptop depends on the style you like. I prefer a messenger bag from Timbuk2. If you go through airport security alot, then maybe the Checkpoint Flyer from Tom Bihn. The Checkpoint Flyer is considered to be TSA friendly.