To us it makes a lot of sense to hold the tablet in one hand and type with the other. That’s exactly how [Adam Kumpf] has implemented this one-handed typing interface which was originally conceived by [Doug Engelbart].
As you can see, there’s a large contextual area for each finger on your right hand. Letters and navigational keystrokes are input through this interface based on single touches, or combinations up to and including all five digits. This offers up 32 possible combinations (including all on and all off) which is enough to cover the modern English alphabet.
[Adam's] demo page works for most tablets so give it a whirl. Yes, it works with iDevices too which is a surprise as we would have thought this was using Flash. If you’re not near a touch-sensitive device you can get the gist of the operation from the demo video embedded after the break.
Now, who’s going to be the first to make this into a replacement keyboard on iOS 5?