Some opinions voiced at Ask Metafilter [1] on wearable keyboards
mentioned the Frogpad, Twiddler and chordite-style keyboards. As
usual people seem to see things differently. Some claim chording is
inherently slower; others like me think it's faster. Some like the
Twiddler. Some hate it. I'd add my 2 cents there but it costs $5 to
post so I'll do it here :-)

A lot of expressed differences at Ask Metafilter and elsewhere are
just apples vs. oranges. The Frogpad isn't quite wearable the way I
define it (the only sensible way ;-): usable by pedestrians in motion.
You should be able to walk while you use it and as a derived
requirement it needs to be tolerant of big motions and vibrations of
your body parts. The Frogpad wants you to use it on a desk or hold it
in your other hand or strap it to your arm. The typing hand has to be
held somewhat steady with respect to the Frogpad but this is a little
problematic when you move around. And if you're sneaking peeks at it
while you're typing, the way a lot of non-touch typists might, you're
apt to trip on something. But yes, you definitely can strap it on and
stop while you use it so many will call it wearable.

Although the Fropad might be easier to learn, in my view the Twiddler
is better as a device for pedestrians. Some find it usable and some
don't. Let me leave it at that. You can google up quite a range of
experiences. I think it's fair to say it's pretty geeky looking as
well. But not as geeky as a Frogpad strapped to your arm ;-)


1 http://ask.metafilter.com/mefi/29178