Here goes a mighty fine job: a test meant to show just how well implemented is the CSS support in a browser. The test starts from a rendering considered corect (reference) and you get to compare that render with the test-page as viewed in your browser. Extremely interesting for a CSS geek like me… 
Update: I just tested all the major browsers against the ACID Test…
FF3 renders perfectly
Opera9 renders perfectly
Safari renders perfectly
Chrome renders perfectly
IE6 and IE7 render a gibberish without any resemblance whatsoever with the final result supposed to be rendered. Now I come and ask: how can this be? How can M$ indulge themselves in such a crass disrespect of the generally accepted web standards? Are their own standards so more important?