For more inflecting power than should exist in a single module, how about Lingua::EN::Inflect? It not only pluralizes nouns like 'cat' -> 'cats', it also handles nouns like 'basis' -> 'bases' and 'church' -> 'churches', as well as pronouns ('I' -> 'we'), adjectives, and verbs. Really, there's more to this module than I can summarize here (hint: the author is Damian Conway) -- just read the documentation! :)