There is an increasing number of Google Webfonts, and its getting super hard to find what you are looking for. Especially since most of them are plain awful. There are a view pearls in there though, which are worth checking out.
Unicode 5.0 encodes exactly 98,884 graphic characters on different planes. Here you can see them all. Decodeunicode.org
WhatFont? is a neat Chrome plug-in that let’s you identify typefaces used on websites with one click. A real time saver.