Nicely done, I love how easy it is to flick between fonts instantly.<p>I would second cleverjake's comment that a neat way to see serveral fonts together would be awesome (Especially for a different headline font vs the body copy).<p>Also, a search for the big list of fonts would be handy too.<p>Off to a great start though, thanks for sharing!
Not functional without Flash:<p>"You don't have a compatible version of Flash installed. Please install latest version of Flash and refresh this page."
Cool tool. The down-arrow seems to jump every-other font on the list. It'd also be good if it automatically loaded the font as you pressed that key to go down the list so you could quickly pan through them all without a lot of clicking.
I built something along the same lines a while back that allows you to drag and drop font files into the browser.
<a href="http://fontdragr.com" rel="nofollow">http://fontdragr.com</a><p>Also has a bookmarklet so you can test them on your own site.