The Apple Garamond font is a unique variation which Apple has used for many years. Apple Garamond comes with the client version of Mac OS X, but it's not installed to use it nor is it in an obvious place. AGex lets you extract the Apple Garamond font to your Desktop folder.
Font Viewer allows you to list, compare, try and print all installed fonts on your system.
FontNuke is a utility application for Mac OS X Tiger that removes corrupt / troublesome font cache files.
Makarra is an app written in applescript studio, which may be useful (and cheap) to manage your fonts.
TrueBlue is a free font conversion utility that converts True Type fonts (TTF) to PostScript Type 1 fonts (PS).
(commercial) Typeset lets you preview, search, and organize your font collection so that you can always find the right style for a project on your Mac.