From the google button page
http://www.google.com/support/toolbar/bin/request.py?contact_type=button&hl=en

"Google Toolbar 4 and the Button Gallery will soon be available in several languages. If your website supports multiple languages, you can provide a button title and description in each of those languages in your button XML file. To specify the language of each title and description, include the locale attribute in each of your <title> and <description> tags. We will also use the locale attribute to determine which buttons appear at the top of the category listings in each language's Button Gallery."

toolbar for IE, last version=4
http://toolbar.google.com/T4/?rd=f

oh thanks for the pointer!