Scribd on the front page of BusinessWeek.com
businessweek.com
businessweek.com
It also has many other useful Google tweaks, like removal of text ads and click tracking.
It looks like Scribd is building a reader for the iPhone, and this app will also allow searching within Simon & Shuster pbooks. This is interesting because it sounds similar to what you can do with Google Books, though on a much smaller scale.
Also from the WSJ article, Scribd's PDFs can be read on the Sony Reader but not on the Kindle DX - which means they've probably adopted Adobe's DRM. Are we going to see DRM-free paid content from Scribd at some point?