I started out with a pretty good bottle of balsamic vinegar - no worries, even though this experiment didn't work I will definitely use this again:
I measured out 1/2 cup of it into the pan, added a little minced garlic, and then followed my instructions from T and the Internets.
I brought it to a low boil then turned it down to simmer. Nothing. It still looked the same, but (as T warned) it got very stinky. I kinda got the onion-eyes thing, as cooking vinegar totally made my eyes sting and water. I kept trying with different heat levels for about 20 minutes, and while I could tell that the volume of the vinegar was decreasing, it wasn't actually "reducing" to the syrupy consistency I expected. I gave up, but the balsamic was still perfectly fine to use.
So I used it as planned in my turkey-veggie wraps. I used multigrain tortillas (the store was out of fat-free, too bad!), with thin-sliced smoked turkey, celery sprouts, spinach, and the super-convenient pre-chopped goodness of "rainbow salad." That gives you carrots, cucumbers, and red cabbage. And I added the balsamic for flavor.
The wraps were tasty and filling. And, that smoked turkey must be pretty awesome cuz this is the first meal I can remember where trusty cat Cleo actually climbed up onto me to *stole* off my plate! She nabbed some turkey out of the end of a wrap, so I did split one open to share with her. (No worries, I handed her little pieces of turkey, she didn't eat off the plate!)