I saw the weirdest thing walking home from the library today...and believe me, considering the area around our library that is quite a statement.
There was this guy (kid really, probably 18 or 19) walking up the street very quickly (what we military folks would call "with a purpose") and he was holding an unopened box of Ritz crackers in front of himself at chest height like a shield. I'm not sure if a box of Ritz crackers can actually protect you from anything, but maybe he was just being extra careful. I have to say that if you want to try this yourself I would probably go with Triscuits....they are roughly the same density and weight as kevlar only with more fiber.