Sorry, have to brag....
We just got back from a trip to Europe for my sister's wedding that involved 24+ hours on planes and in airports in each direction. I was a little uncomfortable NIP before, but I am proud to say I am now a total pro!
On the plane it's pretty easy, because people tend to keep to themselves anyway. In the airports, I started using a cover, but by the end of the trip I didn't even bother. DS doesn't like the cover, and it was just easier not to have to dig out one more thing.
I got no comments of any kind, my baby was fed and happy (I think he even had a growth spurt from how often he wanted to comfort nurse on the plane).
It was a little like learning to swim by being thrown into the deep end of the pool, but I now feel like I can feed my baby anywhere!