Remember to always keep a bag (or bags) on you or with you. Check out these cool products!
Joey Totes http://www.joeytotes.com/
Shopping Bags Etc http://shoppingbagsetc.com/shoppingbags.html
ONYA Bags http://onyabagsusa.com/
You can find more cruelty free products on my page at http://working4change.blogspot.com/2009/09/shopping.html
I do this when I shop. I use mesh bags for produce and cloth bags to tote it all home in. The only thing I haven't figured out what to do with is bulk items like rice or nuts. What do you store those in between the bulk bin and the check out area? I am afraid to use a mesh bag because they would spill out. I suppose if I used a twist tie to hold the mesh bag together...