My buddy Chris Coyer got together with a few of his friends from Paravel and created a wonderous new jQuery plugin called FitVids.js

FitVids.js allows for Flash video embeds to work in a responsive layout. Typically, this is pretty difficult to achieve; often the video will get cut off, or it will have the incorrect aspect ratio. With FitVids.js, all of those problems fade away! Check out the video below to see FitVids.js in action.