Google has launched the Keyboard API and its so easy to use on websites. This is what google has to say:
It is often difficult for Internet users to input text in many non-Latin script-based languages for a variety of reasons. The correct keyboard layout may not be installed on the computer they're using - sometimes such a layout may not be well developed or widely available. This poses a challenging problem for web developers because there is no way they can ensure that their users have access to this very basic input technology. Our Transliteration API can help, but requires that the user know multiple languages.
To use and have a look at a live example follow the url: http://code.google.com/apis/ajax/playground/#virtual_keyboard