Invoking the onscreen QWERTY-keyboard
There are (at least) two ways. You can disable FitalyStamp and tap the spot where the abc-dot is hidden under the Stamp. On my Clie N770 this is easy to remember - it is at the Bottom of the Stamp on the line between the options menu "i" and the letter "q". YMMV
An easier method IMO is using the menu shortcut "/k" which should work in most applications where calling the keyboard makes sense at all. That's also two taps - which can even be simplified by using a custom slide for this.
OTOH, why would anybody call the keyboard in the first place? ;-)