Here's perhaps the most powerful bookmarklet I've ever created ...
This one translates the current web page from your current browser session into another language!

Syntax from the address bar in your FF or Opera browser:

 tr <FROM>|<TO>

Examples:

 tr en|de
 tr en|fr
 tr en|pt
 tr de|en

Here's the bookmarklet code

javascript:location.href='http://translate.google.com/translate?u='+encodeURIComponent(location.href)+'&langpair=%s&hl=EN&ie=UTF-8&oe=UTF-8&prev=%2Flanguage_tools'

FF instructions:
Copy/paste the code in a new bookmark. Then, in the new bookmark properties, edit the keyword/shortcut field and insert 'tr'. That's it!

Opera instructions:
Copy the bookmarklet code. Then, in tools-->preferences-->search-->add-->details, paste the code in the address field, fill in a name for in the name field, and write 'tr' in the keyword field. Then save all. That's it!