score:7
I've had success just asking at the check-in counter. They gave me a "boarding pass to nowhere" (looks like a boarding pass but I can't actually use it to get on a plane) which I then showed to the TSA agents. I imagine they have discretion, and this might vary by airport (mine was in Seattle), so you might want to call the airline ahead of time to make sure.
I've also heard of people buying a refundable ticket just to get past security (and then not boarding and getting a refund), but I've never tried it myself.