Patagonia Lightwire Pack

Excellent low profile day pack to store all your urban gear so that you can get out of the office and find a new place to stir your creative juices. Comes with a laptop compartment, a “desk pocket” for the usual non-digital paraphernalia, and a breathable back panel to wick moisture away from your back. This feature alone might make it a worthwhile purchase. Judging by the quality of the zippers this looks like a long term keeper. Here is a bit on the material used on the outside of the bag from Patagonia:

Doubleweave ShiftLayer nylon fabric combines baselayer woven under tension with floating top layer to absorb friction and reduce abrasion (in the way liner socks reduce blisters by transferring friction to harmless contact between sock-fabric layers).
210-denier, polyurethane-coated ShiftLayer nylon. Lining: 210-denier prismatic reflective nylon

It comes in a number of different colours other than the boring black shown above. More info here.