Brian,
I've been clamping mine to a conveniently located stud in the shop, but this has become a problem for two reasons: I have too many for the space, and some of the vises won't accommodate a nominal 2x-anything. I'm planning to put some 1x shelves in that stud bay. Right now, they're in a milk crate.
This picture dates from a post somewhere a few months ago:

Since then, these have followed me home:


I paid more for the last one, the Goodell-Pratt, than I have for most of the vises in the top picture combined ($1 is a common price for these in yard sales); but, well, it was a Goodell-Pratt.