Have to agree with a previous poster; I would imagine it's more likely that people would stare at the thief running out of the venue, rather than get involved and take a risk.<p>You can pick up a drawstring gymsack for a couple of bucks. It scrunches up to a very small size in your daily carry, and you can ensure any valuables are secure on your back if you have to be away for a short time while the rest of your stuff stays at the table. Low tech, but has been effective for me so far.