Stylizer is a CSS editor that integrates with 9 browsers and lets you make and see changes in real time. They seem to have Sony, IBM and Thomson Reuters as customers, among others (going by the logos at the bottom of their home page).
On their site: "Real-time CSS Editing Saves Time and Money."
The site is visually impressive, IMO.
It seems to be a paid app, but you can download Stylizer to try it out.
- Vasudev Ram - Dancing Bison Enterprises