In the process of reconfiguring my shop (again), I came up with this. I'm sure it's not an original idea, but I haven't seen anything quite like it so I though I'd post it.

Here's where I do my setup work...


And here's the neato' feature that lets me easily get to all sides...


And here's how it works. It's just a piece of 3/4" ply sandwiched underneath the vice. To swivel, I just slightly loosen the vice and the whole thing turns. You do want to be a little careful to make sure the vice and the board turn at the same time!