I posted on PimpMySafari.com awhile back about how I found a hack to remove the tab bar from Safari. I think I actually found the hack on the same site.

Months went by and recently I’ve been receiving a lot of mail about it. People want to know how to do it.

I did a quick Google search and this is what I came up with:

1) Ok you need to have Xcode tools on your Mac.
2) Make a back up of your Safari App incase things go wrong.
3) Right click on Safari and select show package contents.
4) Browse to the english.lproj folder and within that goto the browser.nib folder.
5) Then right click on info.nib and open it with Interface builder.

Now your in the bit that defines how safari looks.
I assume you know how to get the unified menubar look.

6) Click on the TAB BAR section in the window.
7) Then select tools and show inspector, a window will pop up and check the box that says hidden.
8) Save it and reload Safari and the tab bar should now be gone.

If things go wrong you can revert back to your backed up copy of Safari.

This isn’t the way I did mine. Someone offered up their revised version of browser.nib that I downloaded and used. So if this don’t work… I can’t help you.