Could u link me any tutorial on animating lower thirds for a documentary?
thx

take your pick =)

YouTube Search (http://www.youtube.com/results?search_query=vegas%20animated%20lower%20third&search=Search&sa=X&oi=spell&resnum=0&spell=1)

There are some posts on this forum as well that might give you some good ideas.

I also talk about that topic in a couple of my newsletters.