Originally Posted by varuscelli

The second one should be able to be mounted to the seat post, I think. You'd just need to loosen, detach, and rotate the end piece where the bar strap is. I'm pretty sure that's the way it works. Granted, the first one looks a lot nicer, but the second should work, too. (I can't promise the second one will work the way you want it to, but I think it will...)

They sell the second one at Performance Bicycle. I saw them there today when I stopped by for the tail end of their Grand Opening in Houston (Westheimer store). On the package it stated "fully adjustable horizontal and vertical." They're something like $10 on sale right now or about $15 regular price.

Viewpoint Spacebar Handlebar Accessory Mount