Translate in your GoogleTalk!

Google released 23 translation chat-bots yesterday. You just send them a message and they'll reply back with the translation within a second, inside Google Talk or any other jabber client. List of bots:
 

ar2en, de2en, de2fr, el2en, en2ar, en2de, en2el, en2es, en2fr, en2it, en2ja, en2ko, en2nl, en2ru, en2zh, es2en, fr2de, fr2en, it2en, ja2en, ko2en, nl2en, ru2en, zh2en

Explanation on the language codes: 

EN = English, NL = Dutch, DE = German, ES = Spanish, FR = French, IT = Italian, KO = Korean, RU = Russian, JA = Japanese, ZH = Chinese.

Add the bot like this to your buddylist:

<FirstLanguage>2<SecondLanguage>@bot.talk.google.com

This service is hosted by Google, and therefore I bet it's using Google's translation tool. :P
Google also encourage you to create your own bots, if you know programming. :) Since the XMPP protocol is open, you can find a lot information on bot-making on the web.