The one that inspired me was by SlickSqueegie: http://www.instructables.com/id/Shop-mad-bench-vice/ The only obstacle I had was getting a acme threaded rod long enough to do the job. I searched for a while but couldn't get one without paying more than the price of a cheap wood vise (like this one). At some point on this search I had a moment of engineering clarity: I have one of those quick-grip bar clamps , why not use that instead of a screw... so I 'invented' a vise with a low pivot and place for the clamp.
Naturally I had not invented anything, the leg vise has been used at least since the 18th century, see the second picture above. This is a good thing because I could research different styles of leg vises and modify my design.
I've also created a 3D model of this vise, so if you'd like to see it all in more detail you can download it here.
Step 1: Plan / Design
I've included my dimension sheet in the second photo but this will vary depending on the size or your workbench.