There is a utility ukeyboard from Jiri Benc on the Maemo applications with which I made a 4 row (123..., qwe..., asd... and zxc...) finger keyboard, so switching between keybords for letters and digits is not needed anymore.

His application is on
http://www.upir.cz/maemo/keyboards/

UPDATE 20081002 Improved version with 3 layouts:







Here it is:

http://misc.nicejewel.com/en_NL.vkb

and the ukeyboard def file (you can customize it yourself when using ):

http://misc.nicejewel.com/4rows.def

Put the vkb in /usr/share/keyboards and chmod it to 0644. For the unmodified vkb file the tool of Jiri Benc is not needed.

Then a 'language' "Four rows English" will show up in the control panel under Languages.

Have fun.