Is anyone familiar with glucomannan?

I happened upon a suggestion in Women's Health magazine that adding glucomannan to food makes it increase in bulk and has the effect of making one feel fuller. It also has the added effect of vastly adding to your dietary fiber intake. After googling it, it seems that it could possibly have other health benefits but, apparently, there isn't enough research on it yet to make many substantial claims. Since vitacost.com has it on sale for $10 (for 180 caps), I thought I'd check it out, but wanted to see if anyone here was familiar with it first. I'm also asking over on the Alternative board, in case someone there has tried it.

~Marin