I thinkyou might be a little confused about what is/isn't allowed on a plane

The FAA is concerned about RF (radio-frequency) emissions. The concern is that it will mess-up aircraft navigation/communication.

A number of people on this board (including myself) have expressed the opinion that cell phones/etc are not as dangerous as they are made out to be.

That said, you probably want to play it safe and NOT use anything that uses RF.

This means NO BLUETOOTH-it's RF

IR though, is just LIGHT. It's wavelength is MUCH MUCH MUCH longer than bluetooth.

IR is what your tv remote uses, it's present in sunlight. So, there is no more risk using IR keyboards on a plane than using a flashlight!

So, to sum it up, get an IR keyboard

Just search on google for "ipaq 1945 IR keyboard"