The Psion netbook project back in 2004 modified Abiword and Gnumeric to run with a touchscreen interface (and thus only one button, with 'click' and 'clcik-and-hold'). It also reduced the menus to move less-used items to 'other' with a few other changes for the relatively small screen (1024x768 IIRC). That work was done by the abiword and gnumeric devs under contract so I assume all the relevant patches have been in the codebase for some time, and hopefully made the Maemo port easier.
If any of that stuff never got in (and concievably could still be useful), I presumably have it lying around on a computer somewhere...)