Google Translate for iPhone has been optimized for speed, supports all of the
existing Google Translate language pairs, and uses a client-side
data-store on your iPhone to hang on to your past translations so you always have them at hand, even if you can't use the local data network.
If you are with an Olympian who doesn't understand you, you can hold up your iPhone to let him/her read a translation You can get between 200
and 400 translations in 1MB of data download.
To try Google Translate for iPhone, point your iPhone or iPod Touch web browser to www.google.com and choose the "more" tab. Or you can go directly to translate.google.com in your browser.
The Goolge mobile blog suggests "If you are traveling this summer (perhaps on your way to Beijing?) we hope you find this useful."