Hi
Once upon a time, John M. McIntosh built a spellchecker plugin for the MacVM and there was a fileout that added a spelling service class to use it from Squeak. We have added code to provide the same API (for now) to windows and linux users that have ispell (or a compatible program, like aspell) installed on their systems using system callouts.
A metacello configuration is available from the MetacelloRepository on Squeaksource, ConfigurationOfSpellingServices.
The development repository is at http://www.hpi.uni-potsdam.de/hirschfeld/squeaksource/SpellingServices.html, the repo has global read+write, so if anybody finds this useful and has changes, feel free to commit to that repository.
-Tim