I looked for it in System>Preferences>Keyboard> Layouts tab >Button "+ Add" > By country, select Brazil, Variant, see if "Thinkpad" exists. In Hardy it exists, in Jaunty, it doesn't. Some people in IRC #ubuntu confirmed it also doesn't exist in Intrepid.
AFAICT, the only key that's different in this variant is the slash/question, that in the default variant is the right Ctrl.
Although the "thinkpad" variant doesn't show in the menu, the following command activates the
setxkbmap -model abnt2 -layout br -variant thinkpad
I looked for it in System> Preferences> Keyboard> Layouts tab >Button "+ Add" > By country, select Brazil, Variant, see if "Thinkpad" exists. In Hardy it exists, in Jaunty, it doesn't. Some people in IRC #ubuntu confirmed it also doesn't exist in Intrepid.