This colorful bag from Baggu ($8, baggu.com) may look fragile but the sturdy nylon fabric holds as much as several regular shopping bags. It comes in a rainbow of fun colors, stripes and prints including 11 different shades of green. Wear it over your shoulder or fold it into a tiny pouch when it's not in use. Super-sizing your shopping? Check out the Big Baggu ($14) with capacity enough to stash a few beach towels.