It's about all those plastic bags . Charging for plastic bags (currently illegal in California ) is a growing way of trying to get people to stop using them. Germany charges about a dollar for one, Ireland about 30 cents, Ikea a nickel, Whole Earth takes a nickel off for each one you don't use.
Remembering to bring along your recyclable bags (often forgotten at home or in the trunk of your car) is a habit it's hard to get into.
I've found a great item that goes with me all the time - an ultra-compact bag. I've been using my Chicobag for more than a year now and it's still in perfect shape. I found it in a local store but it turns out it (and other brands) are available online . The Chicobag  site (that's Chico, CA) has a nice section on using them for fundraisers.