Don't see that this has been posted before...Sorry if it has!
Kindlefish -
http://kindlefish.t15.org/ - languge translation site for Kindle. It's a 'front end ' site for google translate which doesn't work well on Kindle browser...I just tried it and it is very cool!! Here's a link to a description and review-
http://www.wired.com/gadgetlab/2011/...al-translator/
EDIT: Currently for 3G on 3.1 (and a patch for DX), not K2 or K2i ....Bummer
EDIT: 4/5/2011 Now works with the K1, K2, and DX.....very cool!