What Font Is - Find any font from any image (commercial or free)
AMP Font Viewer - Jump to Download - Download.
Font Manager - Simple font management for GTK+ desktop environments
FontScanner - FontScanner is an application that helps you to find any font name, type, size, color, and family.
FontFace ninja - A browser extension to identify and try fonts on any website
WhatFont - The easiest way to identify fonts on web pages