Nate Klaiber 05 December 2011 I have a question in regards to separation and ownership. I think other’s have covered some of the other dangers, but I also agree with Drew that those can get ironed out over time. I am glad you put options out. 1. Who own’s the media query breakpoints? What if a member of the UX team changes or adds to those breakpoints in the CSS files (owner), won’t they have to remember to update the in the PHP file? 2. Precompiling. I think since you know the possible breakpoints up front, that you could write some PHP to precompile (cache) all possible assets, which means all requests will hit the cached image. You won’t be using PHP to re-size on the fly (which could negate the point of it taking less time – as it would take less time to download two images then have PHP write new images files on requests) Thanks for showing us your thought process.