Those who scoff or lament the fact that the iPhone has no physical keyboard might be persuaded to try out this gizmo, which is available exclusively on November 18 at Thinkgeek.com.
The TK-421 iPhone case ($49.99 U.S.) has two models - one for the iPhone 3GS and one for the iPhone 4. Though the iPhone 3G has the same form factor as the 3GS, Apple never included Bluetooth keyboard support for it in subsequent iOS updates, so this case won't work with it.
Even though the iPhone is nestled inside the case with a magnetic clasp, the connection to the keyboard is purely wireless via Bluetooth, meaning there is no option to use the dock connector for a wired setup. This is significant because Bluetooth can be a battery drain, especially on the 3GS. It also doesn't help that the keyboard has its own battery built-in, so you will need to ensure that both devices are charged to make this marriage work.
You also have to deal with the case's extra girth and weight. Flip the keyboard underneath the iPhone, and the handset becomes a little tougher to snuggle into a pocket. Making it a bit more plump doesn't help portability much, either.
That said, the premise behind something like this is obvious. The iPhone has a touchscreen that offers no tactile feedback when typing on it, so the keyboard remedies that. And since it's used in landscape mode only, you get full screen real estate to type into, as opposed to having half of it taken up by the touch keyboard.