This past February was the first time I flew with my little man...and what a perfect gentleman he was !!!!!!!!
I flew Jet Blue and they only allow three pets per flight as "carry on" I would check with specific airline you are planning on flying with to find out the specifics. After the experience I had I would never hesitate again to fly with my boy, I was having all kinds of doubts and nervousness before hand but all worked out awesome!
I don't think I would have traveled with him if I had to put him in cargo