this is another stuff to translate by using Google, you need just to know what it's "JSON", example :
http:
documentation :
http://code.google.com/apis/ajaxlanguage/documentation/
maybe (I don't what you've do in your application), reason for your slowly application, is you translate each word at time, not all words in one time.
many requests/responses + low bit-rate = very slow application
. try to translate all words in one time and separate them by delimiter before translation.