The Window Titlebar in Mac OS X Tells You When You Have Unsaved File Changes
Not sure if you have unsaved changes when editing a file in Mac OS X? Just look at the window titlebars close button, if the red close button has a darker red dot inside of it then you have unsaved changes.
I use this frequently as an indicator for when I should quickly hit Command+S but I don’t think it’s widespread knowledge and I was reminded of this by TheMacObserver, who also points out that the little mini-icon next to a filename in the titlebar is an indicator of when a document needs to be saved.
These just a few of the many subtle things in Mac OS that make the operating system so great.