Plastic bags

Some states in India have apparently banned the manufacture, sale and use of all plastic bags, saying they choke drainage systems during bad weather.
Here in Australia, some states are also working on this. There has been a push towards encouraging shoppers to use "green" bags and most major retailers either sell them or give them away. Some have even come up with fold up bags, easily carried in bag or backpack - otherwise it's a bit difficult to "say no to plastic bags".
I miss plastic bags though - they were the right size for the rubbish bin in the kitchen which we now have to buy bin liners for. I guess that means they get our money both ways - but I suppose it's worth it if it helps the environment. Whatever happened to the idea of biodegradable plastic bags? Some are on the market - I know, we buy them for the cat's litter (wouldn't want anyone to find this still in the bag in a couple of hundred years time!).