CustomTankBags by LindaT.
These are special purpose bags built to your specifications. Quite a few long distance riders have auxilliary gas tanks to decrease the number of those pesky and time-consuming gas stops. This 'bag' covers an auxilliary tank and adds storage space where there is none. Special purpose pockets can be made that could hold water bottles or whatever you need. Unfortunately for me, auxilliary tanks come in a variety of shapes and even more different attachment methods, so each one of these is truly tailored for the bike it's on.
Optional Features list: