One of the more obvious design oversights on the earlier Yuba Mundos (not sure if it has been fixed with the V3) is the lack of bosses for mounting a bottle cage. Hauling a heavy load can be thirsty work, and the sheer comfortableness of the ride means that inevitably people start using these bikes for longer rides.
Handlebar-mounted bottle holders are available, but the only place I could find one was online, which meant paying delivery and waiting around. I decided (quite a while back) to use what i had to hand instead; a Topeak adjustable bottle cage and the mounting bracket from a Kryptonite U-lock. The Kryptonite lock mount comes in two halves held together by an allen bolt. One half is the clip for the lock and the other is the strap which clamps onto the frame. Using the bolt and a washer, it is easily possible to mount a bottle cage to the strap part through one of the screw holes, the end result is function and looks like this: