I too, travel a lot. The DX is my first Kindle. I travel mostly from a small airport and haven't been asked to move it from my bag to date. I've traveled through Mexico City and Newark recently, and no one has asked me to remove it there either. I was only asked to put my bag on its side in Newark - well, I wasn't asked, I was berated by the nasty TSA person there. Most of the people in that airport are nasty anyway

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I have the M edge platform cover for my DX and I found that I could prop it on the tray table when I travel coach. I was a little nervous with a 3 year old boy who was sitting next to me, playing with his cars, but there were no incidents to report.
I love the idea of keeping pdf's of my directions that I get from the web right on my Kindle. I'll be GPS-less when I get to my destination this week, since my boyfriend needs my GPS more than I do, but the Kindle will come in handy. Thanks for the idea!