You guys got the screwdriver thing right. Thanks BostonTrevor for the graphics.

The nipple tool I've seen is like an offset screwdriver with a spinning handle. You can assemble wheels like crazy with it...but I doubt if it would work if you had to apply any significant torque.

Yes, I'm sure I could buy a tool specially for nipples but my LBS is closed by the time I get home. I can always find cheap tools at the grocery store. I've modified (improved?) quite a few.