We currently have a number of images (especially those in root/static/images/icons/, with a few exceptions) that we use only via the CSS background property. To reduce the number of HTTP requests necessary to load these files, they should be combined into a single image a la the CSS sprite technique.

We already do this for some things – see http://musicbrainz.org/static/images/layout/sprites.png, which includes the header logo and our rounded corner images – but we can and probably should do it for many more things.

Alternatively, our supported browsers all support data: URIs (http://stackoverflow.com/questions/1765342/which-browsers-support-data-uris-and-since-which-version#1766942 – the IE8 limitations are that it "only supports data URIs for images in CSS, <link>, and <img>." This technique would allow us to reduce our extra connections for images to 0, since they could be entirely embedded in CSS.