Views on a Domain Model
Instead of pulling an enormous object graph in-memory and bring the contained data on the users screen we decided to use so called Views on our Domain Model. Roger Johansson is developing a UI mapper (he calls NView) which generates such view models on the fly. Paul Wilson invested his time on a similar concept named UIMapper. Mats Helander wrote a series of articles on this very same subject. Interesting?
So now we use a resultmap in iBATIS to map directly against a CustomersOrdersView. By using raw T-SQL/Views it is pretty easy to optimize a view displaying aggregated data.
Fabrice Marguerie mentioned Martin Fowler's page about the PresentationModel  and John Gossman's weblog  on Avalon's ViewModel.