I usually carry a small, lightweight backpack with sometimes rain gear, water, peanuts, and room for a couple of bobbles. Do I now have to carry a purse? 
My rain gear quandary was solved by .... ponchos. I can carry a nice poncho in the string bag Gburg wrote about or purchase a 97¢ "emergency" poncho at Walmart. I put the emergency poncho in my back pocket and then toss it out when I'm done.
