If you only speak English traveling to a foreign land or even the local taco house can be a problem if most of the people that work there speak Spanish or another language. I once had a housekeeper that only spoke Spanish, which was rather convenient for her since you could only tell her you needed her to clean the fridge by texting her daughter after she was out of school.
What I needed was the new Google Translation app on the iPhone that has launched now. The app is really cool and instead of having to fight the crap predictive spelling that seems to get a thrill out of using the wrong words when you type, you can speak what you want translated. The app gives you a printed translation of what you said and can even speak it back so you don't have to try and pronounce the phrase correctly.
The app supports multiple languages including Chinese and Spanish for 23 total languages supported. You can download the app on the App Store right now at no charge. It will work on iOS 3 and later on the iPhone and iPod touch.