For the last year or so I have been flossing my teeth by first tying together the ends of around 12" of floss, thus forming a loop. The benefit of doing so is that it doesn't slip through my fingers when (wet and) I want make the floss taunt; I simply pull my hands apart.
I realize that there are devices that can hold floss between the ends of two small rigid arms, but I have found them ungainly compared to using my fingers. My dental hygienist said she would like to have floss in loops too. Floss that is manufactured in loops would sell better than the standard spools available today, I believe. It would make a nice product (just give me a piece of the action and some free samples for the idea).
UPDATE 2004-06-10 10:05:
Last night David pointed me to a website of a manufacturer, Floss Loops. I will try to find a way to buy it.
Doing a quick patent database search with the string "floss loops" yields a number of patents relating to floss loops.
It's a good idea, though.