OS X has some built-in ways to tell at a glance if the document you’re working on has unsaved changes, which is pretty helpful if you’re like me and constantly get distra—ooooo, look, Duke Nukem Forever is out! No? Aw, sad panda.

Anyway, if you look at the window’s Close, Minimize, and Zoom buttons (the red, yellow, and green circles that appear in the top left) while you’re working on a document, you’ll note that the red Close button will have a dark dot inside it if you have unsaved changes. As soon as you hit Command-S or choose File > Save, though, the dot goes away, and you’re back to the more familiar appearance of your buttons. This works in lots of places, including Mail, TextEdit, all three iWork applications, and some third-party programs like TextWrangler and PDFpen.

Here’s how the Close button looks with no unsaved changes (top) and when you need to SAVE, SAVE RIGHT NOW (bottom).

Another cue about whether you’ve made changes is the document icon that appears next to the name of your file in some programs. If that icon is grayed out, you need to save before you walk away from your machine or, say, start doing Internet searches for vaporware.

And here’s how the document icon changes to give you another visual reminder to save.

Why should you worry about saving your documents, you ask? Because apps crash, and losing your hard work really cuts into Overkill time.