Hi all,
I had the same idea as Fred Smedley (yes, J-B Weld and all). So I figured "Well, somebody needs to try it...." . I would certainly not try this with the intention of downhill or single track, but for a touring bike, I'll give it a go.

I've got 5/8" with no threads, 7/8" threads with J-B Weld applied and sanded down. Sure, I would rather have 1" without threads, but I don't. Check the pics. I think it does add a bit of strength (maybe I'm wrong). Also, the threads won't leave grooves in my stem.