Just type the address of the relevant website into the box and then click the link. Rather neat: I shall bookmark it...
UPDATE: since it's a vaguely related in that it is a technical note, here is a neat little tip for using Quick Look to examine fonts in Mac OS 10.5.
In the Finder, select a bunch of fonts and hit the space bar ... clicking any individual style reveals the core character set for that font, along with buttons for paging through the collection one font at a time.
Very useful for those of us with literally thousands of fonts.