If you're using a keyboard without an eject key, say a non-Apple keyboard, an older Apple keyboard or (in my case) a really old Apple keyboard, you're probably missing that eject button. Sure, you ...

Click the Eject button in the Finder sidebar to eject a disk. (Note: I’ve reordered the sections in my Finder sidebar, so your may look slightly different.) ...

X disables CD tray close button? Fred Wagner notes that after installing Mac OS X on his G4/533 MP, he can no longer open or close the CD tray via the keyboard.