SVGMagic is a simple jQuery plugin that searchs for SVG images (including background-images) on your website and creates PNG versions if the browser doesn't support SVG.
Wondering why you should use SVG images? SVG images are vector based! Meaning that they will be as sharp as hell no matter how big they are. In other words: one file for every size. See it yourself: (assuming you are now using a browser that understands SVG images)
That's where the fine part comes in: almost nothing! Just download the SVGMagic.js script include it and initialize it.
SVGMagic will now check every image on your page and changes it to a PNG version if the browser doesn't support SVG.
More information about SVGMagic? Check the Github page or scroll down.