Also are included are tabs to place at top-right, top-left, bottom-left, bottom-right.
There is also an auto option which places no widget but if the end-users browser language is different to your site language the Google translation bar appears. Thus a totally unintrusive option for most of your site users.
Translates over 50 languages.
Provides translations in most European, Asian and some African languages. Most major markets covered.
This module has backend language localization for English, French and German.
No need to register.
PROs: Easy to install/implement, doesn't break your template, Option to have no Google logo plastered on it, no POWERED BY garbage either. Nice and clean!
CONs: See first comment, other than that NONE
This one doesn't do that. It works well and won't break your template.