Twice in the last couple of years, I've been lucky enough to coast into a gas station and right up to a pump - out of gas...
And also twice in the last couple of years, my riding buddy has run out of gas and I rescued him with enough gas from my tank to get us to a gas station.
My crossover line between tank sides has a quick disconnect coupling, and I carry a piece of gas line with the matching quick disconnect coupling in my tour pak. It's my version of the "Fuel-Tool" - just a whole lot less costly. 
Same here Scott. Of course it only helps if I still have gas and I want to give a little to someone else. Doesn't do much for me if I run out and need gas however.

btw, I ran mine down to fumes on the first tank of gas when the bike was new, thanks to a defective fuel gauge. It took 5.4 gallons to fill it to the bottom of the filler neck. From what I've heard from several folks since the change to the 6 gallon tanks, there doesn't seem to be as much of a "reserve" on those.
As for the Fuel Tool, I don't fully follow why I would want to buy one of those versus just buying another quick connect fitting (probably have to buy the fuel line assembly, about $60 MSRP) and adding some extra line to it. As best I remember, just turning the switch on with the engine not running will also run the fuel pump until the pressure regulator shuts it off. Why would I need to have the engine running and a tee connector? I don't know, maybe I'm forgetting something.
Jerry