When I made my Roubo bench I used a roughly 5" section of 3/8" steel rod as a pivot pin for the parrallel guides on both leg vises. I don't move the pin often, but when I do it's a bit of a pain to grab that little pin, especially when the vise is almost closed.
I'm pretty sure I got this idea from a picture of Lie-Nielsen's new Roubo bench, posted on Woodworking Magazine's weblog. The area of the picture was a little blurry, but it planted the seed, and I went with it. So credit to Lie-Nielsen Toolworks for this idea.
So I lengthened the pins, then inserted them into a turned handle. The pins are now much easier and quicker to grab and reposition.
The pin for the sliding vise is a bit longer since the rear chop on the slider is wider.
After using the handled pin a few times I realized that some thought and effort was required to avoid over-inserting the pin in the parallel guide's hole. Pushing the pin in too far places the handle between the jaws and prevents the pin from seating flatly against the leg. If part of the handle goes past the edge of the leg, the parallel guide would mash that part of the handle into the leg when clamping.
The solution was to stop the pin at a fixed location without interfering with the function of the pin. Anything larger than the pin's diameter would't work. My solution was to drill through each pin and drive in a 1/8" roll pin.
This makes changing holes truly brainless. It's impossible to over-insert the pin.
Changing pins in the parallel guide is quicker and easier than ever.