DarkDiamond.net

The guys over at 4 Leaf Studios (a group of guys from 4chan's /a/) finally managed to prove that the entirety of the site isn't completely useless when they come up with a great idea and has produced an excellent demo of the first Act of their eroge "Katawa Shoujo".

http://katawashoujo.blogspot.com/2009/04/katawa-shoujo-act-1-preview-released.html

Go check it out!