Rails 3

I am porting an applicationto rails 3

Reading about I18 in rails 3 guides I learned that there now are a
default key using the . operator based on the name of the view
e.g t(.stupid) in view users/show.html.erb would assume the key

I tried something similar in my first attemp with I18 but found then
that this key convention results in a lot of transaltions of the same
That conflicts with the DRY principle but could be a more effective
way of using keys from a rails point of view

I use now the simple key views.stupid but could change to the rails 3

Any preferences for using the proposed default keys based on the name
of the view instead of some other simpler keys ?
How to avoid repeating the same translation?
What is the best practise when it comes to key definitions?
What is new in I18 in rails 3 as compared to rails 2.8?