Just an update on this project: It didn't work for ****.

I tried running two brake cables through a modified bmx upper gyro cable thingy, so that they could both operate the single front brake. However, there was so much friction in the cables that the brake spring was not strong enough to return to its open position. I think this was due to the fact that, one, the brake levers were cheap-o Nashbar tt levers, with no return springs, and that, two, the brake cables curved sharply along the bends of the tt bars.

I think that this setup could be made to work adequately if the cables were less restricted and the brake levers had decent return springs. Also, the cheap brake caliper that I used (Shimano Sora) may have played a roll in the unfortunate outcome of this $8 experiment.