I received one of these as a gift for my most recent birthday and I love it.  The AmeriBag® "Healthy Back Bag®" has a patented, ergonomic design that contours to the natural curve of the spine.  The design of the bag is such that its weight is evenly distributed (as opposed to being at the ends of the straps).  

The product is available in a variety of colors, materials and sizes.  The interior is well planned (it includes a key fob) with lots of organizer pockets.  

There is a shoulder strap pad that comes as an accessory.  It keeps the bag in place and provides added comfort. 

More information can be found at:  http://www.ameribag.com

Here's to a lighter load,
Alma