Over on the Judaism site, HodofHod implemented an integrated virtual keyboard for typing Hebrew:
This seems like an idea that could easily be extended to other languages/scripts: German, Chinese, Russian, etc. For some sites, it would be helpful to have more than one keyboard. (Hebrew and Greek for the Bible site, for instance.) While nothing is stopping people from forking the code and extending the idea, it would help a lot more people if the feature were built into the various sites.