I don’t recall where I found this otherwise I’d give them credit…

What is the easiest way to find out the fonts used in a webpage? Firebug or Webkit Inspector? No, that’s too complicated. It should be just a click away.

WhatFont Tool can easily get font information about the text you are hovering on. There is a Bookmarklet and Chrome Extension available for download. I am sure it will make web designer’s life much easier.

Source: I’m sorry – I don’t remember.