I've cut back on flying this year so I don't have to deal with TSA nonsense, but the last couple of times I've flown, they specifically said if the electronic device has an off button, turn it off. So there you go.
I read the inflight magazine or tat* until the plane reaches altitude. And then I prepare my ebook evangelization spiel because my neighbors and the flight attendants often ask about it!
*since someone usually asks:
tatting I use
plastic shuttles, so no problem with TSA.