I use one and wonder what I did before I got it. there are several reasons to have one, to whomever wondered.
I have this:
http://www.roadtools.com/podium.html (Targus coolPad) it works great for a non-fan-driven stand. my (17") powerbook stays quite a bit cooler (I'm sure my fans appreciate that) and I like the position it sits in, makes typing easier.
I often keep a lot of intense applications running and my poor powerbook heats up pretty fast, this has helped and eases my mind a little. I treat this thing better than I do most people
so its performace and environment is always on my mind [haha]
uh, sorry, losing my train of thought...
yes, they are good and worthwhile. unless your laptop gets really hot rather often, a non-mechanical one might suit you best. less power-drainage, less hassle, less weight, less money (usually)
you can get a used one so long as they say it's not broken... (that is another reason to have a non mechanical one, what can really happen to them then?)
go for it... thumbsup
from me anyway.