On Noupe : The Mobile Web: CSS Image Replacement for Retina Display Devices
With the evolution of technologie, more and more devices get the retina display capability. For those devices, serving normal images results in an ugly interface, with pixelized graphics. There are some solution to serve those devices high quality images using the min-device-pixel-ratio CSS3 media query, combines with some background-size.
I created a tutorial to explain the technique :