Thought: do data urls work in .css files? e.g. background: url(data:....); ? Because then you could have one cacheable file (everything.css) that sits along sid

Thought: do data urls work in .css files? e.g. background: url(data:....); ? Because then you could have one cacheable file (everything.css) that sits along side your pages (use background images instead of plain old imgs), so you would only have to download them once, not on every page load.