The mini-foodgeek has a small vise on his workbench that he uses to hold random scraps of wood so he can cut them into smaller random scraps. Most of what he's been cutting lately has been dowels, and the flat jaws that came with the vise didn't work very well for the task. Here's how to turn some scrap aluminum into a pair of vise jaws with a v-groove to hold round material.
You'll need access to a mill, some 3/8" thick material, and a 60 degree drill-mill. Being mill-less at home, I made it at techshop