This is a WordPress plugin allows you to use a shortcode like this:
[translate_this lang="fr"]un texte en français[/translate_this]
To automatically insert Google's Translate Web Element which creates an AJAX-enabled link that will translate the block of text in-line.
For more information about the Google Translate Web Element, click here.
Exported from code.google.com/p/gtranslate-web-element-for-wordpress
FAQ:
The default base language is English. If you put the short code around a block of English it doesn't need to translate it. Also, check the two character language code is supported by Google Translate. Make sure you have the lang parameter in there and the value is language you want to translate from.