If you need to remember what a screen message looks like -- whether it is a warning, a pop-up, or even a setting you don't want to forget -- try this.
First, use Command-Shift-4 to grab a screenshot of the region (press the Space Bar to just capture the window if you want). OK, a lot of users know that already. However, once you've grabbed the screenshot, slip it into iPhoto, and create an album named something like Warnings or Apple Messages, and you've created your own memory reminder tool.
I have used this trick for mail settings, internet connection speed tests, my wireless settings, questions I have when I go to a One on One appointment, and general reminders of other various settings. Try it, and you'll never again have to guess "Now what did it say?"
Mac OS X Hints
http://hints.macworld.com/article.php?story=20080711115715639