Here are two views of my Versa-Vise. I saw it on a Stewart-MacDonald video and liked the fact that it could be used in two different ways. Attached to the workbench is a vertical rod. You slip the Versa-vise over the rod, either for a vertical, standard positioning of the vise, or on its side for another orientation. What's neat about it, too, is the fact that you can swivel the vise 360° around. The jaws are nice and wide and smooth, and can open to around 4 inches. Once you tighten the vise's jaws, the entire vise also locks into position, without your having to also tighten another handle. It really has proven to be a "versatile" tool.
***** NOTE *****
This particular vise seems to be hard (or impossible) to find nowadays.....BUT there is a very similar vise, called the "Parrot Vise," now sold by Grizzly Products. Here is the link to the URL describing this "Parrot Vise". Also...here's a review written by Frank Ford of Frets.com.