The days of having to turn off your cellphone when boarding a flight are nearly done. Southwest Airlines just became the latest US carrier to allow personal electronics use during all phases of flight. It's the seventh major US airline to do so.

Though Southwest seems quite happy about the decision — taking the opportunity to advertise its inflight Wi-Fi services — the company cautions that not every personal electronic device can be used. "Bulky laptops and devices larger than a tablet must be stowed during taxi, takeoff, and landing," the airline warns.

Since the Federal Aviation Administration (FAA) ruled in late October that the radio signals from personal electronic devices didn't pose a threat to the safety of aircraft during takeoff and landing, the airlines have moved quickly to relax their previous restrictions. Delta and JetBlue were the first to change their policies, quickly followed by American, United, Alaska, and US Airways. Now that Southwest is on board, the only major carriers remaining are Frontier Airlines and Virgin America.