OS X includes a couple of handy utilities for dealing with symbol characters in fonts—you know, things like the copyright symbol (©), the divide character (÷), the registered trademark symbol (®), and the Euro symbol (€).
First, there’s the Keyboard Viewer, which shows you the various symbols for a given font face: just press and hold some combination of Option, Shift, and Command, and the on-screen keyboard will display the special symbols that each keystroke will generate. The Character Palette is more comprehensive, and shows you literally every symbol you can create from any font (but it won’t show you the keystrokes necessary to generate that symbol). It can also show you thousands of Unicode characters, which you can either copy and paste, or type directly in Unicode-capable applications using the appropriate four-digit hex code, as displayed in the Character Palette.
There are a couple ways to access these tools—you can open the Character Palette directly from many OS X applications. Just look at the bottom of the Edit menu, and look for the Special Characters entry. If it’s there, select it to open the Character Palette. This works in lots of programs, including the Finder, Safari, Mail, Smultron, and many more. The other alternative, which is also the (apparent) only way to open the Keyboard Viewer is to use the Input Menu, which is represented by a small flag icon on your menu bar. (To activate the Input Menu, open the International panel in System Preferences, and click on the Input Menu tab. Enable the Character Palette and Keyboard Viewer checkboxes, and your region’s flag should then appear in the menu bar.) Click the flag, and you can choose either the Character Palette or the Keyboard Viewer from the drop-down menu. (Quick side hint: make the Keyboard Viewer notably larger by clicking the green button; I find it much more usable at the larger size.)
Unfortunately, this means that some of your precious menu bar space is taken up by the Input Menu, even though you may rarely use the tools it holds. Wouldn’t it be nicer if you could put these tools in the Finder’s sidebar or toolbar, or directly in your Dock? It turns out you can do just that, as both of these utility panels are actually small applications.
To add Character Palette to your Dock, sidebar, or toolbar, navigate to /System -> Library -> Components, control-click on CharacterPalette.component, and choose Show Package Contents from the pop-up menu. In the new window that opens, navigate into Contents -> SharedSupport, where you’ll see CharPaletteServer. This is the actual program that displays the character palette, so just drag it directly into your dock, sidebar, or toolbar—do not move the program to a new location; leave it right where it is.
To add Keyboard Viewer, return to the Components directory, control-click on KeyboardViewer.component and choose Show Package Contents from the pop-up menu. In the new window that opens, again navigate into Contents -> SharedSupport, and then drag KeyboardViewerServer to your preferred dock, sidebar, or toolbar location.
Presto, instant access—just click on either entry in the (for example) sidebar, and the application opens nearly instantly. Once you’re sure everything works, you can disable the Input Menu (by disabling any checked items in the Input Menu tab of the International System Preferences panel), freeing up valuable menu bar space.