If you thought that you could entertain yourself onboard a flight in Japan with your PSP or Nintendo DS then you are in for a rude surprise. Apparently, "passengers on commercial planes [in Japan] are no longer allowed to play games using wireless connections with handheld consoles." The ban includes the DS and Sony's PSP, personal headphones and mice that are cordless.

There goes your chance of spend a few hours of unadulterated pleasure of gaming in the skies!
Source