I'm dreaming of an 8 gallon tank...

If it were me....
I'd extend the bottom of the tank. Thru the frame and where the airbox is. Just use a ramair intake. No one would even notice, and all welds would be hidden. Just have to mod the intake straw and ignore the fuel light...
Saddlebag gas is probably the cheapest, easiest, and least complex way to go, like IMFASTTOO proposed, but I'm much more interested in pursuing the approaches mentioned by "BigNorm" and "camccardell". After all, if I'm going on a longer, endurance type ride, chances are I'm going to have other provisions packed in my saddlebags, like food, clothing, rain wear, etc. I'd rather have my fuel where, ( In my mind ), the fuel should be. I admit, it's a preference. There's no right or wrong here. We all have our individual opinions. And, we are all entitled to have our opinions, ( silly as some opinions may seem to some of you ). We should all be trying to support each other on this forum, and when we disagree, do so in a constructive manner. What's the point of one-upmanship here? We're not children. Although, I'll admit to being a child at heart. Why else would I want to ride for hours without taking a break?
 
I love the idea of using the air box for fuel. In fact, that is how the Honda ST1100/1300 bikes are set up, with the main tank up top, and a smaller tank below the seat.

Now if someone would just figure it all out, and buy two of everything, selling me the second set.
 
Heres a thought...get a set of Mitzzys quick release brackets, build a platform the includes everything needed (tank, pump, etc), make it quick connect to bung in the tank and some electric and voila...an easily configured long distance setup. Not much use to you touring guys, but easily doable on a standard or roadster. Now if you can just get your back tire to last long enough...
 
Curious, I don't see the first thing about fuel there. There must be more there than meets the public eye.
 
I've just started reading their archive of wisdom. Good stuff. I wasn't aware that on days 3-7 most people can only physically handle 65% of the distance that they could on their first day. Good to know.
 
I like the way your thinking but wont fit a touring