Naked Objects
Very interesting concept, for prototyping and maybe more.
This reminds me of an application framework that I created back in 1932 (or slightly later, it's this age thing again) with Clipper, where one only had to define a data dictionary to get a rough yet workable data management application.
The naked objects goes much further, and I like the idea of empowering users by exposing business objects to them.
note: if you don't know what Clipper is, you might have been born too late ;-)