See link for "wristlet armor". There is a specific word for that type of forearm accessory, that I've been trying to remember. "Braces", maybe.
Anyway, they are plenty large enough that a smartphone could be mounted on one, so its length stretches along your forearm.
You wear it kind-of like a wristwatch. As a bonus, if you are wearing a jacket or other clothing that is covered with solar cells (resembling "scale" armor), you can provide plenty of power to the smartphone, so its battery doesn't run down.
As another bonus, you could obtain a smartphone app that uses the phone's build-in motion sensors to detect when your arm moves from the "dangling" position to the about-to-be-used position, and the app would display the current time and perhaps other default stuff on the screen.-- Vernon, May 18 2012 Wristlet Armor http://www.google.c...urce=og&sa=N&tab=wiAs mentioned in the main text; various images [Vernon, May 18 2012] Scale Armor http://www.google.c...0...0.0.68CLLlJKv4cFashion designers, take note! This is how solar-cells can become clothing! [Vernon, May 18 2012] Flipout http://m.gsmarena.c...la_flipout-3271.phpWorks well on a wristband. [8th of 7, May 18 2012] Trendy Sporty Wrist Strap for ee-telephone 4 http://www.case-par...one-4-IPHONE-4-324/Commercially available from cheap Chinese importers... come on Vernon, keep up! [pocmloc, May 18 2012] Baked, but possibly not Widely Known To Exist. Works well with a Motorola MB511 Flipout.
<link>-- 8th of 7, May 18 2012 //"Braces", maybe//
Close, either braceRs (archery) or VAMbraces (armor).-- MechE, May 18 2012 [MechE], thanks. "Braces" may also be correct, though. After all, "Bracelet" means "small brace", right?-- Vernon, May 18 2012 'Bracelet' comes from 'bracer'. 'Braces', in garment terminology, are what we in the US know as suspenders.-- Alterother, May 18 2012 There are also plenty of concept phones out there, where the phone itself wraps around the wrist.-- neutrinos_shadow, May 20 2012 random, halfbakery