If carrier bags are banned what will you pick up your dog's poo with?

Photo from heatherspetcare.com

Carrier bags are very wasteful, we all know this, and gradually they are in the line of fire more and more. Environmentalists, supermarkets, governments are all coming up with ways to use less and reuse more.
However, we've missed the fact that many carrier bags are already reused by dog owners. The trouble is the bags are then chucked away. Shouldn't dog owners switch to a more environmentally friendly faeces receptacle. Also, it is likely, carrier bags will be done away with and everyone will use a longer lasting sturdier bag to shop. So what will dog owners use to pick up their dog's mess?

What do you think? Dog owner or not their must be some good alternatives out there.
Here are my thoughts: