If you're a chick, this works great for small amounts.

Take a UNUSED maxi pad and slit it down the middle. If necessary, take out some of the filler, have your weed inside a couple of baggies rolled long and thin and tuck it inside the pad. Who the fuck is going to want to check out a cooch that's bleeding?
Oh, and they make scented pads if you feel the need to disguise any scent. Either that, or don't shower for a few days......;0