OS X,General Tips
Key Caps vs Font Book
Looking for Key Caps? Key Caps is a utility that is used for (among other things) finding special characters that aren't printed on the keyboard keys. In 10.3, Key Caps disappeared in favor of Font Book. Strangely enough, though, Font Book doesn't let you insert special characters into a document. To get the Key Caps functionality back, open System Preferences, and click "International". Click the "Input Menu" button, and put a checkbox next to Keyboard Viewer. Also check "Show input menu in menu bar", at the bottom of the window. This adds a menu near the top right of the screen from which you can select various keyboard layouts. Now you can choose "Show Keyboard Viewer" from this menu to display a floating window that allows you to browse special characters by holding down different combinations of modifier keys (e.g. the command key, command + shift, command + option, etc).
