CSSTidy is an opensource CSS parser and optimiser. It is available as executeable file (available for Windows and Linux) which can be controlled per command line and as PHP script (both with almost the same functionality).
If the examples are accurate, it certainly cleans things up.
In a larger sense, however, I’m interested in articles about how people organize their CSS in large scale projects. I have a large application with hundreds of CSS rules. How do you group those in to logical units which may or may not correspond to separate files? Not every page uses every rule, so how to do I organize the CSS to make the pages as efficient as possible and easy to edit. I’d love to see some best practices here.