Is there a free cloud translation tool?

What would be really nice would be if a user is running my application and it detects that the main language on the computer is not english, it automatically converts all text into that language, and not just the menu bar and title bar (that can just be stored in an array,) but text in the files that get loaded.

It would be really nice if I could do something like
http://www.translator.com?aFrom=english&aTo=french

POST data:
Hello, I speak french.
The dog is black.

and have it come back with:
Bonjour, je parle francais.
Le chein est noir.

I know of lots of web translation tools, but I want to translate just what I want and have it come back with just what I want, so I don't have to search through a web page for it. Does anything like that exist?

In you use these web translators to translate english to language-x, and then reverse the translation back to english, you often see that the web translators did a very lame job of things. If these data files are pre-packaged with your application, it might be better to have pre-translated sets of data files and select from them with a setup option. And have those pre-translations done by someone fluent in each language.

This doesn't answer your question, but as starry eyes said, automated language translation software is in a very primitive state, and I don't suggest using it. Because words, phrases, and grammatical constructions can have completely different meanings depending on the context (and that's not even counting slang and other colloquialisms, as well as typos) and because no two natural languages have an exact one-to-one mapping, computerized translations are always inaccurate for sufficiently large input samples (which often means only one or two sentences) in the status quo. Some people hypothesize that software translators will never reach the level of human translators, even given centuries of technological innovation. Some languages, like Chinese, don't even have the notion of tenses, while with others like Japanese, the distinction between present and future is blurred. Also, Japanese doesn't conform to the traditional SVO or SOV paradigms of Indo-European languages because it doesn't even really have the concept of a subject. Topics are similar, but they aren't always equivalent to subjects in English. To account for such extreme syntactical differences in languages, it really seems like you need humans to understand the context of a given passage.

I found GTranslate, run by google. I know that the language tools suck. If my company ever puts out a non-english site, I'm sure that they will pay for a professional translation, I just need a rough one for developing and demoing.

I just realized that I've only ever used it for one line translations, via the url. I hope it supports POSTing.