I haven't finished mine yet, blaming the usual life's distractions, but we know better.
Anyway, I got a couple heavy truck brake drums, welded some C channel to the top, and to that I welded on some 2" square tubing, with the top about my elbow height. I have the next size up square tubing which fits over it (okay, it doesn't fit so well; I didn't buy the stuff without the ridge inside) and to a piece will be attached a 20" or so diameter piece of 1/2" steel plate. Drill and tap some holes near the edge for work holding, and we'll see how it does. I have some of the larger tubing cut to 3" pieces, welded together at right angles (welded on nuts to secure them to the 2" square tubing wherever you want), with the plan to put little arms that stick out where I want them, and bringing a vertical out at some convenient spot. I can either use one of the added arms to mount a vice, grinder, seat for my butt, or whatever. Sort of a modular system. At this point, I have two posts on the drums, and my vice mounted to the top of one. Life changed, so did my ability to finish them shortly after I started. Holds my vice really well, with the heavy base the next best thing to being mounted on my workbench, but with more access and function (just not the weight capacity, unfortunately, but I couldn't put a breaker bar on my workbench either) I plan on doing a couple more, and by mounting a larger table top to two drum posts, I can make a larger table. It just keeps getting heavier if I let it...