Here's my current workflow for editing CSS:

1. Me: "Take a look at this page!"
2. Guys: "Try making the post titles bigger"
3. Right click on a post title, choose "inspect" (to inspect it in firebug)
4. Find the appropriate CSS statement in Firebug (`h2.post_title` or something)
5. Modify the CSS in Firebug, ask friends how it looks
6. If it looks good, make the change again in Textmate

I want to avoid step 6. I.e., I want the ability to edit CSS via a Firebug-like UI and be able to commit my changes to the relevant file immediately (rather than having to copy them by hand as I do with Firebug)

**Edit:** Something that works on a Mac would be ideal