A short note in case some people are interested: I just built Voikko, the open source Finnish spell-checking software, for Nokia N800. Instructions are available on how to install it. Note that I only very shortly tested it from the command line ("works, good"). I mainly wanted just to try reprero to do something, which provided to be very easy.
Apparently the ISP I used to host the files does not allow directory browsing. The Sources.gz file tells the whole story, ie. I also built and provide enchant, hunspell libraries which are not included on the tablet itself.
Addendum: I also tried building AbiWord to test Voikko graphically, using Ryan's instructions. I built the needed packages gsfonts, fribidi, libgsf (newer than maemo 3.1's libosso-gsf), libwmf and wv - they are now available in the same repository as Voikko. I quickly tested the AbiWord I built, but removed it from the repository as for some reason I didn't get hildon UI even though it should have been configured, eg. no keyboard input, and also because the plugins would be very much welcome too and I had some problems with those. But I did load up some text file and succesfully tested the spell-checking feature of AbiWord in Finnish, and it worked fluently :)