You've been meaning to gather enough re-usable grocery sacks to do away with plastic bags all together, but you just can't find the time to sew them all, and can't bring yourself to pay $8-9 for commercial products.
A better answer: purchase some cheap tote bags from the craft store. Those living in the Midwest, Southeast, Oklahoma, and Texas should note that Garden Ridge sells large tote bags in, like, 15 different colors for only $1. These beat the pants off the reusable bags that are appearing at the grocery store for the same price (or more): they're made of an identical material, but they are twice as large (big enough for two gallons of milk), they come in a variety of colors, and they are without advertising- so you can use them in any store and won't feel like a big walking, grocery-shopping commercial. Plus, if you're inclined, the large fabric surfaces would be perfect for painting, stenciling, or screen-printing your own design.
For example, here's a similar (perhaps identical) bag punched up by Yo La Tengo:
These bags are great for shopping at local markets and co-ops, hauling books to and from the library, and did I mention they are only a dollar?!
Click here for Garden Ridge locations.
Know of other stores around the country (or the world) that sell similar products? Post 'em below.