We started translating drupal to french, that is the fr.po file, a few months ago. Not much has been checked back into CVS for now, although I have finished translating the book module.
We are still looking for help to translate the rest of the po file. It is not hard to do, you are encouraged to participate. Check out our project web page: http://drupalfrancais.zapto.org/, and get in touch with us.
Some sites out there are at various stages of translation, you are welcome to share your translation with us so everyone can benefit.