I have an '05 LC. Toyota says "NO" to flat towing.
That said, there's a dude on IH8MUD.com who has a LX470 with lots of flat towing mileage. GX models are have a very similar drivetrain.
Personally I didn't want to risk killing my transfer case by towing (lack of lubrication as the input shaft isn't spinning, or so they say), so I traded my wife's Pilot in on a GM 4WD sport-ute. Win for her, and I get to keep my LC ;-)
Looking back, I should have gotten a Ford Expedition. All you have to do to tow (besides installing base plate etc.) is shift T-case into neutral, and enable "flat tow mode."
GM vehicles require disconnecting battery which I think is quite inconvenient, even with a switch to do so.