A few months after we moved to Vancouver we got Nexus cards. For $50 and a background check, we can now cross the US-Canada border in special expedited lanes. The signs that declare PEACE ARCH CROSSING 45 MIN WAIT now translate to "ten minutes in line and two questions from the customs agent." We also get lighter security screening on intranational flights and don't have to talk to a human being when we fly into Canada from the US.
Sometime last year the TSA decided to acknowledge that those of us who'd been through the Nexus screening program were unlikely to be a terrorist risk, and opened the "PreCheck" security lanes to Nexus cardholders. Attempts to use the PreCheck lanes last year met with frustration at every turn: the lanes were only open some of the time, the people working the lanes didn't know who was eligible and who wasn't, PreCheck is only available for entirely domestic flights (if you're flying out of the country, clearly you are going to blow up the plane on your way out.).
Today the stars aligned. After a pleasant train ride down and a tasty lunch with imperatrice at Katsu Burger (I am only surprised that the people selling deep-fried hamburgers are Japanese and not, say, Texans at the state fair) I arrived at SeaTac at 12:30. Plenty of time to wait through the ridiculous security lines and still make my flight. On a whim I wandered over to the PreCheck line, just to see what they'd tell me this time.
They scanned my boarding pass and ... just waved me on through. I hauled my luggage onto the conveyor belt (didn't have to remove liquids or laptops) and walked through a normal x-ray scanner. Total time from entry to exit: maybe five minutes.
This seems like a reasonable way to run an airport security line. Now to entertain myself for an hour and a half before my flight.