Script Summary: new banner added, blue colour scheme implemented, minor layout changes.
There are probably some holes in it, as I only played with the home news feed look and profiles, but most other things seem to have fallen into place. Not sure how adverts will look, as they're either adblock'd or greasemonkey'd out for me, but I'm pretty sure I've removed the obvious ones anyhow.
Basically a Stylish script adapted for greasemonkey, thanks to nl5unh for their comment on my style.
UPDATE (12-April-2007): Redone for new site design. Few minor problems still, but I've only spent 15 minutes on it. Screenshots now not up-to-date, but give the general idea.
Screenshots
Before
After
