It depends what you want to do.
In a web page it is best to get the scope if you need it and dispose it in the pages dispose method. In a app. server or fat client app you should complete your usecase and dispose the scope after you are done.
If you do not have such places you also can use the scope as singleton, but you should avoid using it in more then one thread at the same time.
the Telerik team
Check out Telerik Trainer
, the state of the art learning tool for Telerik products.