Luggage cart for Camera Bag

I have an F-Stop Loka (which I love) that I use for all of my hiking, but I also fill it up with all of my camera gear and use it as a carry-on when I travel. With a full load of gear it becomes very cumbersome to lug through the airport. Have any of you come across any foldable luggage carts you can recommend? My only requirement is that it is foldable and is small enough that I can either store it under the plane seat in front of me or under my bag in the over-head compartment. Thanks!

Im not sure about the luggage cart, but I would think that may call more attention to the weight of your bag and increase the chances of you being inspected. I continue to see the airlines in the US getting more and more picky with carry on luggage. I check all my clothes and carry on a Think Tank airport security V2.0 roll on and either my Think Tank UD60 or Think Tank Shape Shifter, depending on my needs. The heavy stuff is in the roll on and they never seem to give it a 2nd look since it looks just like normal luggage.

lowepro roller bag is a good option.
i think i saw one for sale in the FS section.
you can see pics in my review links.

and it fits in most international/domestic carrier luggage requirements for carry on...
i've only had one issue, an oversold shuttle from Paris to Milan, they complained about my bag and so quite simple, take out the liner, ship the case and shut them up in a jiffy.