I found this little jewel at Harbor Freight tonight, and it really works. This is a digital torque meter, that has an adaptor both top and bottom that lets you clamp it into a vise and use it to test torque wrenches, among other things. It's a pretty simple device, with an electronic load scale built in and a socket and adaptor on each end - seems to be accurate to tenths of a lb/ft or n/m or whatever scale you like to use, although the range is limited from about 10 to 150 lb/ft
I checked both of my torque wrenches and found that my old 1/2" drive was off by about 10 lbs, where my inch lb wrench was spot on.
So if anyone has a torque wrench you'd like to test and possibly calibrate, we have the tool to do it now - as long as you don't have a super cheap on like mine that's not adjustable for calibration. So next shop day, bring your wrenches!