Sainsburys will be charging 5p a bag from September, even more incentive to reuse bags. I imagine more supermarkets will follow suit.
I bought some large and very substantial carrier bags in an Italian supermarket and after three years they're still going strong. If only we had them here, they are virtually indestructible and made from recycled plastic.
France has also led the way in getting rid of poly bags. You cannot get flimsy carrier bags in supermarkets, you can only buy heavy duty bags for life. We have to take our own bags even if we go the DIY store.