France deserves credit for their doggy poop bag system! Often while walking in cities or villages, you see a system where they have made an attachment to walls or entrances to parks etc to get your own poop bag with you - free of charge! Well this gives comforts too all citizens, with or without dogs.
Other thing what many communes offers is that you can pick up your bags freely from the town hall, how great is that! I got this set of four rolls and the holder.
This is something that many countries could take as a model!