Translating text between languages is an interesting problem to solve -- and solving problems is a perfect way to use some of the extra brain power that can be found at Google.
I decided to give something a shot -- what would happen if I tried to translate a page without giving Google any information about the language it's written in (or what language I speak). Google knew everything I didn't tell it. For a good example of what I mean, we use Wikipedia since it is available in multiple languages. Let's try translating the Spanish version by using this link.
In the past you would have needed to specify your language "hl=en" and a language pair ("langpair=es|en"). Notice how we didn't specify any of that in the URL above? On the Spanish version of the Wikipedia page, click "Deutsch" to try the German Wikipedia site. Notice how even that site is in English? It's also interesting to note that the frame Google once put at the top of translated pages is now gone.
Theoretically you could use this proxy as a type of Babel fish by using a Firefox extension that passes page requests through this service. Users would have the comfort of knowing text is always presented in a language they understand (as long as Google understands it).
You might then wonder if an extension like this would affect browsing speed. It might cause a bit of a performance hit, but in most cases it shouldn't make much of a difference. Translating pages that are initially in your native language will skip the translation related processing and send you directly to the requested resource. For example, this link forwards you directly to http://en.wikipedia.org even though we are trying to use the translation service.
One day people will only need to know a single language for access to everything on the Internet -- a service like this is a great start to that end.