Like most Google apps, Translate for iPad is lean and uncluttered. It basically serves as an interface for Google's own back-end system, which is where most of the legwork happens.
Since this app requires Internet connectivity to do its job, it might be less than ideal for many international tourists. WiFi may not always be easy to find each time you need a language check, and unless you're very sure about your international roaming data plan, leaving it up to 3G could prove to be an expensive gamble.
But besides those particular circumstances, Google Translate can be very helpful. Its library contains dozens of languages, from Afrikaans to Hindi to Icelandic to Maltese to Yiddish. It even has an automated language detector if you're unsure what you're dealing with.
Its translation power goes both ways. You can find out how to relate a Dutch phrase to an Arabic speaker, or Welsh to Japanese, or vice versa. And a language swap button at the top will reverse the direction of the translation for quick back-and-forth.
Once you have a result, you can star it for future reference or expand it so that it fills your iPad screen with big block letters (which could make you look pretty funny to native speakers if your translation happens to be a bit off). And if you're dealing with one a few widely spoken languages, the app can also listen to spoken input and pronounce the result out loud.
You can't point Google Translate at a fast-talking speaker and expect an immediate transcript. Even slow speech often comes through muddled.
But if both parties speak clearly into the mic and check to see that they've been correctly understood before handing the iPad over for a reply, language barriers will be broken, communication will happen, and it'll be a lot easier and informative than a spontaneous attempt at charades