Is there this kind of software:

[drtwin]

Is there any kind of OS utility or enhancement that allows one-handed use of device without using touchscreen, like it is on WM2005?

[littld]

I use ButtonMapper to achieve this sort of result.

For example:
I press the first key (Contacts I think, by default) to:

- go up one level in File Explorer
- go back one page in Internet Explorer
- load my default playlist in Media Player
- mute in the Phone app
- switch between different zoom levels in RepliGo
- launch Start menu from the Today screen

I use the top and bottom button (voice record and camera by default) to:

- scroll up and down in the Calendar and ToDo apps
- turn the display on and off in Media Player and default
- record and stop recording in Notes
- rotate the screen

And when that sort of solution fails me, I fall back on MS Voice Command!