San Francisco has banned plastic bags.  Craig Noble, a spokesman for the Natural Resources Defense Council, said it would be disappointing if grocers rejected the biodegradable plastic bag option, since more trees would have to be cut down if paper bag use increases.  Well, this is typical of San Francisco - they allow themselves to be led around by a nose-ring, held firmly in tow by eco-nuts.  Heaven forbid that trees should be sustainably harvested!  Oh - and never mind that plastic bags can be recycled.  They're - well - plastic bags!