Of interest for someone who will have an extended stay in a city, and whose lodgings include at least a kitchenette, the Tom Bihn Shop Bag might be useful for small scale shopping:

http://www.tombihn.com/accessories/TB0608.html

Or, if you live in San Francisco, which has just outlawed plastic shopping bags, and now requires that a ten cent charge be made for even paper bags, one of these would pay for itself in four or five years, or....perhaps after the first trip, if it makes the difference between dropping a bottle of wine or not!

i have this shopping bag. the large and the small. truly a well made bag useful in many situations. the handles are great because they have poron in them. carrying heavy load will not hurt your hands. the handle will not bite into the palm of your hands. i turn mine inside out so that you have those two inner pockets on the outside rather than on the inside. this way you can put stuff on the outside. toronto is about to ban all plastic shopping bags, hoorah!!!

Funny you should mention these. I use one as my bag to carry to work since it's so comfortable and convenient to carry over my shoulder. I can put my lunch in the center and pull out a banana during my walk, as well as using the pockets for my headphones and phone and miscellany. I have two and after years of hauling stuff and being used as beach bags and shoved under airline seats they have a few small holes but these don't get bigger thanks to the dyneema grid.