The people at Sitepoint send me a 'Tech Times' newsletter every now and then. I tend to ignore newsletters from most other companies, but this one is different, it is surprisingly interesting, most of the times.
Today's Tech Times (issue 246) informed me about Less, an improvement over regular CSS that adds variables, mixins, operations and nested rules to regular CSS. It's backwards compatible and compiles to regular CSS before you serve it to your favorite user agent. Wow.
This is definitely something I intend to integrate into the work flow for the PensioenPage technology, right before optimizing the (normal) CSS using the YUI Compressor.