You can input a word or phrase for translation by typing the text or by talking into the phone. The new iPhone app accepts voice input from 15 languages, and just like the existing web app, lets you translate that phrase into one of more than 50 languages.
You can also listen to your translations spoken out loud in one of 23 different languages, including Arabic, Polish, Portugese, and Hindi. The app uses the same speech synthesizer voices that were introduced in late 2010.
The linguaphiles here at ReadWriteWeb were resoundingly skeptical of the recent release of Android's translation app, contending that "Given the wide range of languages, accents and intonations in the world, we probably shouldn't expect this to be much more than a gimmick yet."
I'm not sure I'd call this a gimmick, but nor it is the answer to all your translation needs. It is, nonetheless, a pretty cool translation app and some of the new features make it more useful than just the ability to have foreign words read aloud. The app lets you enlarge the translated text to full-screen, for example, helpful for reading the text or for showing the translation to someone you're communicating with. There's the option to spell out the translation of non-Latin script languages (such as Chinese or Japanese) in Latin characters to read it phonetically. And there are also dictionary results for some words single words, and - a helpful feature to avoid international roaming charges - you can access your starred translations and translation history offline.