I have bags that I keep in the house, and bags that I keep in the car, and even one hanging from my purse, but somehow, too often I end up at the store with only one bag. When we don't have enough, I use paper bags, because we use those for other things around the house, then I can compost or recycle them.
I collect natural history, environmental, and geography books, almost compulsively. I look for used versions where I can (to save paper) but also appreciate that many of these books come out in runs of a few thousand copies, and aren't profit-makers for the publishing companies, so when they come out new, I buy them while they're new. If you like Geographile and want to let me know, please either comment on my posts, or visit my Powell's wishlist to feed my book collection. You might find books you like there, too.