Yup. Although the way you put it, Broonie, it almost sounded seedy
You would install a specific skin and texture that is fitting...and it would all occur in a closed off area for the 'setting'. I guess it would probably work alongside some kind of external info delivery system for quest notes, etc. Maybe a simple flash doo-dad. You see a sign in the game that says "read note 3-2", you'd click that box in the flash doodad and it shows you a piece of text, an ambiguous screenshot or a picture puzzle.
I am not speaking of fantastic RPG per se, maybe more akin to a puzzle/adventure.
I could go to an RPG server but why leave the CF|UK server we all know and love