From This Link
The status bar (the thin little bar that shows how many items are in your window and how much drive space you still have available) was at the top of every Finder window back in Mac OS 9. In earlier versions of Mac OS X (including Jaguar), the status bar was off by default, so you had to turn it on, and then it appeared at the top of your Finder windows. In Tiger you’ll find the status bar info displayed at the bottom center of every Finder window by default (well, that’s true as long as your toolbar is visible). If that’s the case, why is there still a menu command called Show Status Bar? That’s because, if you hide the toolbar, it hides the status info at the bottom of the window, so you need the old status bar back. It’s still off by default, so to turn on the status bar, first open a window, hide the toolbar (see previous tip), then go under the View menu and choose Show Status Bar. (Note: If you don’t hide the toolbar first, Show Status Bar will appear “grayed out.”)