The Federal Aviation Administration has decided that passengers can now use Portable Electronic Devices (PEDs) during all phases of flight. The agency recently reviewed the long-standing ban on the use of devices during take-off and landing, but found that there was no scientific evidence to back up claims that such devices interfered with aircraft electronics and communication systems.
While the ban has been lifted, the FAA says that it is "providing the airlines with guidance" and that "expanded use [of PEDs] will not happen overnight." The agency expects airlines to allow passengers to safely use their devices in airplane mode, gate-to-gate, by the end of 2013.
Cellphones usage during flights is still not allowed, by the way:
"The FAA is not considering the use of cell phones for voice communications during flight because Federal Communications Commission (FCC) regulations currently prohibit any airborne calls using cell phones."
Passengers looking for tips on this subject can check out this FAQ on PEDs.