Apple - Is there a good automatic time tracking tool for Mac OS X

Not sure it'll do everything you've asked for, but Time Sink is pretty powerful and can generate a variety of reports. Its almost free at $5 and you can try it for 14-days. It can also run in a menu bar only mode so its out of the way.

I'd like to recommend my own app Timing (see the screenshot below). It automatically tracks which documents you edit, which websites you visit and which apps you use, so that you can later review what exactly you have done. You can also manually add offline activities so that they don't get lost.

As an associate of Touch Studios, an app developing company, I recommend our time-tracking app Finch. Finch does time tracking in an automated way: With the option to start the program on login, it runs in the background, records what windows you have open, and learns how to tag them based on your customized preferences and past behavior. At the end of the day, you get a bar chart showing where your time went. It's a really great app if you have trouble with the traditional 'stopwatch' type apps.