I just spotted something interesting tonight. I work at a ****'s Sporting Goods, and I saw some blank golf club shafts for sale for $10 each. These are carbon fiber driver shafts, and are plenty tough enough to be used for a spreader bar on a bridge hammock.
For us shorter guys, or for handy folks who could do some modificating, they can also be used as one-piece trekking poles.
I'm picking up a pair of them tomorrow, so I'll let you know how they work!