I've never had a problem taking photos from inside a plane. In fact, last month on an ATL-LAS flight, we flew over the Grand Canyon and I grabbed my camera (it's professional-grade equipment) and was happily clicking and the F/A in First Class (as well as a few people in First Class) wanted to see the pictures I took, so I was showing them via the screen on the back of my D300. No problems whatsoever.

Of course, I wasn't taking pictures of the flight crew, passengers, airplane, etc.

Also, in regards to photography inside of planes, venture on over to Airliners.net at some point - they've got thousands of photos that are taken inside an aircraft.