How does having the page title in the title bar help with that, though? It only shows the full title of the currently selected tab, but can't you usually tell which tab that is from its content?

No, not if they're all the same website. Take 3 comment pages on hacker news, for example, you'd have to look around the page for context to know which was which if you had several open at once.

Use a tab manager add on like Tab Mix Plus. It is the first thing I install on any new installation of FF. You can rename tabs or set a minimum width to see more of the title.

Plus numerous other customizations.

When the solution to a problem that nearly every user will have is, "Use an add-on", then that's clearly a time when the design/dev team should go back and re-think their implementation. I can see the phone calls now, "Yes, mom - you need to go install an add-on. What's an add-on? Well, maybe they call it an extension - depends which screen you're on. What's an extension?" Ugh - awful idea.

And then you end up with the old Netscape Communicator suite, until someone wants a "fast" minimal browser, maybe by moving some of the features out of the main browser into extensions....

It's the circle of life!

recently sites seem to be inverting the useful info to the beginning of the title, but this is still a problem. Especially considering that even when you only have a few tabs, the space given for the title is way too small (at least in Chrome, firefox is better about it)