[Android Software/Hacking General [Developers Only]] codesplice:
Keyboard Manager [APP]

App Name: Keyboard Manager (v.1.1) Keyboard Manager (v.1.4)

Developer: ne0fhyk

Price: FREE $1.99

NOTE: This app requires root!!

It took me quite a while, but I finally weened myself away from requiring a physical keyboard on a mobile device when I got my NexusOne. With the multitude and variety of available software keyboards available for Android, I haven't really missed the physical keys. The only annoyance at this point is that I find keyboards that work great for one-handed operation in portrait orientation, like Swype or 8pen (if you're in the mood for adventure and don't really care how long it takes to get a message completed ;) ), but are next-to-worthless for dual-thumb landscape input. With a physical keyboard, you'd just slide that bad boy out and away you go. For those of us with only a touchscreen and maybe a few additional buttons, it can be a bit of a chore to manually change the selected input method each time we rotate the device. If only there was a way for the device to read my mind and select the appropriate keyboard.....

As luck would have it, XDA member ne0fhyk has provided us with a solution to this difficulty, in the form of his Keyboard Manager application. Simply select what keyboard you want to use in each orientation (I use Swype for portrait and SwiftKey for landscape), and the app will handle the tedious business of choosing the appropriate input method. It's that easy, and it works.

Mostly. The app is a bit of a hacked solution, and requires root permissions to be able to get around the Android security feature which prevents applications from changing the input method. Installation is not always straight-forward (instructions are available in the first post of the application thread, and it may cause a few software keyboards to force-close if you change orientation while the keyboard is displayed. The current version (1.1) has come a long way from the previous releases in terms of usability, stability, and reliability, and I haven't had any major issues with it. I highly recommend that you give this application a shot and see if it will help you out with your input needs.

Update (2/23/11): Keyboard Manager is no longer available for free, but is now installable from the Android Market. The now-current 1.4 version has fixed most of the install issues and should be a very easy set-up for you. If you run into any issues with the purchased version, please contact the developer - he helped me solve issues specific to my device, and the application works like a charm now.

Verdict: A functional hack to auto-select the appropriate software keyboard based on device orientation.

Screenshots:

1) The optional persistent notification icon. Activating the notification will give you quick access to the Keyboard Manager settings page, and I recommend you leave it enabled until you get things set up the way you want. After that, disable the persistent notification at your own risk (the persistent notification keeps the process in the foreground and prevents Android from terminating it).

2) Settings screen

3) Selecting which keyboard to use

4) Demonstrating that the app has automatically selected Swype for portrait...

5) .... and SwiftKey for landscape.

(tested on NexusOne / Kang-o-rama 1.2 T1 (CM7.n13 / GRH78C / Android 2.3.2))