I'm shocked at how many of you can't get another drop in after it clicks off! I'm always able to squeeze another 25-50 cents in, and once was able to squeeze in over a dollar! without spills! When I'm taking long trips (greetings from Sunny Debary Florida, btw) I always fill it up as much as I can to minimize gas stops.
After it clicks itself off, listen and you can hear the bubbles popping and the gas draining down into the tank. It takes a very light touch, but seriously, I can get another quarter to half-dollar each time. Just wait for the gurgling to end. That extra half-gallon could translate into 10 miles you need at the end when you're looking for gas in the Georgia backcountry.
The scariest event was back when I still had the Xterra, and a pump near Quantico, VA didn't have the fill detector. I was standing a good distance to the rear of the car, when all of a sudden gasoline came SHOOTING out of the gas tank.. like a fountain all over the side of the car, the pump, the island, everything! I removed the hose and more just kept shooting out of the tank for a few more seconds. I replaced the hose in the pump, ran to the driver's side, turned the car to On without starting it, put the car in Neutral and pushed the car away from the pump. Got it up to a good roll and a good distance away, jumped in, started it and gunned it outta there. Gas was just pouring along the ground out of the station. Gave me a freaking heart attack! I watched in the rear view mirror for a fireball but it never happened. Sheesh.
Oh, Exxon/Mobil Super for me as much as humanly possible. I also have the speedpass in the window and on my keychain, so the pumps are often ready to go before I get out of the driver's seat. Something that comes in handy in our cold Northeastern winters. Jump out, fill it up, replace the hose, replace the cap, close the door, spin around to grab the receipt, jump in the car and GO!