I think most people would agree that, despite HTC’s best efforts, Windows Mobile was not really designed to be finger-friendly. While the various Touch keyboards can be quite good, they often have the fatal flaw of using up a lot of screen real estate, and covering up the very elements we are trying to access. This issue is not usually apparent with the built-in stylus-centric windows mobile keyboard, as its much smaller and most software are already adapted to its possible presence.
HTCExtFun is a small piece of software that addresses this issue by simplifying the change over from finger-centric to stylus-centric Soft Input Panel. The HTC Touch Diamond and Touch Pro have sensors in the stylus slot which allows the device to know when the stylus is slotted or not. HTCExtFun takes advantage of this information by transparently switching between different keyboards on the fly, which should go far in reducing the level of frustration the above issues can cause.
Which keyboard will be brought up can be configured in its registry settings; by default it switches between the Compact QWERTY and the old Windows Mobile keyboard. Its recommended that a shortcut to the software be placed in \windows\startup as at present it does not start automatically.
See a video demonstration of the software below.