Thanks for the info!
I guess I would say I don't feel like I would need to do it all the time. The question came about because I won't my home charger installed until a week after I pick up the car Sunday. I was looking for chargers other than super chargers around me and noticed a few offer free charging. Then I got to wondering what happens if I was at Whole Foods, then go to Target, and if I am low and only have 110V, I would want to try and charge up. Ultimately, when I have the charger at home, I don't think I would do plug in constantly when out.
You will need to bring along, use the Tesla J1772 adapter that comes with the Tesla vehicle. While charging using the J1772 adapter, when you walk away the Tesla vehicle will lock the doors and the charging port. Someone can unplug the J1772 cable but they will not be able to remove the J1772 adapter.
There is a short video on the Tesla site that demonstrates how to use the J1772 adapter. First, insert the J1772 charging connector into the J1772 adapter. Then insert the J1772 adapter into the Tesla's charging port. (To open the charging port cover the Tesla vehicle must be unlocked, awake. You can also open the charging port from the main Tesla screen. From the Tesla's charging screen you can start, stop charging. You can also unlock the charging port.
To remove the J1772 adapter and the J1772 charging connector you press the trigger on the J1772 connector and should hear a relay click in the charging station. The Tesla's charging port has a light that should change from green (while charging), blue (charging completed) light blue/grey (unlocked.) Grasp the J1772 adapter with your left hand as you hold the J1772 connector in your right hand and squeeze the trigger and pull both the J1772 adapter and the J1772 connector from the Tesla's charging port. If you just pull on the J1772 connector it will come out of the J1772 adapter leaving the adapter in the charging port. The Tesla will try and close the charging port but the J1772 adapter will be in the way. If this happens, the Tesla charging port will re-open with a fault indication. Just re-insert the J1772 connector and remove both the J1772 adapter and the J1772 connector at the same time as you squeeze the trigger on the J1772 adapter. Everyone who uses the J1772 adapter screws this step up at least once, nothing bad will happen. (Don't forget to remove the Tesla J1772 adapter from the public charging cable, take it with you. The Tesla J1772 costs almost $100 from the Tesla store.)