I understand not allowing non-passengers through security because it diverts security resources away from the task at hand and can serve to unnecessarily lengthen lines.

However, I've always thought that airlines (or airports) should be allowed to sell gate passes for $10 or $15 per occasion, which would more than pay for your share of security costs, and would discourage large-group access through security (e.g., not many people will pay $75 for a family of 5 to see Grandma off on her flight).

I'd be happy to pay $10 or $15 bucks once in a while to visit a friend who may have a 2-hour layover in a nearby airport. Sure, the "refundable ticket" trick works, but one worries about doing that too often; it might start to attract unwanted suspicion.