Cairngorm is either a National Park in Britain, or a micro-architecture for computer software development. I’d prefer a National Park, but I for work purposes I’ll need a way to show the investors that we know what we’re doing.

Cairngorm is a lightweight micro-architecture for Rich Internet Applications built in Flex or AIR. It is a collaboration of recognized design patterns centered around MVC, and makes it possible for medium to large teams of software engineers to deliver medium to large scale Rich Internet Applications.
For Flex and Air, several frameworks have been developed or are in progress; namely Cairngorm, PureMVC, and Flight. Cairngorm is the earliest and most prominent in this vie for popularity, so it stands to reason that the search starts here when building a large RIA. Following an architecture is asking a lot from independent-thinking engineers. Especially when Cairngorm forces you to go through some painful hurdles just the send and receive data (for example) to a database.
But, for job survival more then anything else, I think renegade coding is a path to disaster when a person leaves a project, since the next person is left wondering if there was any thought put into the long-term success of the project. Although I really value renegade, agile, rapid application development or whatever else you want to call it, it honestly does pay to set up some rules and slow down every once in a while.
So, although I hate the speed bumps, I think Cairngorm or some other structure is a good idea for RIA projects that require several developers. But for my one-man projects which are devoted to wild ideas, I’ll stay lean and fast thank you.