This YouTube video has proven to be useful to explain to organisations why Enterprise Architecture is useful. Description from the YouTube page:
Meet Michael, he works at a your company. He needs support from IT to do his job, so they cater to his wishes. But Michael is not alone and many Michaels later a Hairball Architecture will grow unless you use Enterprise Architecture (EA) to prevent that. EA is not just about some guidelines and principles, it is a process that makes sure the constant changes that inevitably happen in your landscape are good for your company as a whole and over time, not just good for the problem at hand.
The animation and narrative was created by T36 (http://www.t36.eu/) based on interviews with me.