Reader Clark Semmes of Baltimore knows exactly what I'm talking about in today's column -- this guy thing about taking reusable shopping bags into the supermarket and eschewing plastic. "Personally," Semmes wrote this morning, "I feel that the blue reusable bags that Giant Food sells are the most macho.  They are certainly better than the ones sold by Whole Foods or Trader Joe's.  But somebody needs to make reusable bags in purple and black with the Ravens logo on the side.  I think that would kick this thing into high gear.  If they could be made out of greasy denim or recycled footballs that would be even better."