Tom Moor has launched a new site aimed at providing free, high-quality content for professional designers, architects, engineers, or anyone.
In Tom's words,
"it [cadyou] was born out of frustration for having to hunt through mountains of rubbish files, both for sketchup and autocad to get to the good stuff."
cadyou already has a nice collection of content; however, the success of the site really depends on user contributions. Anyone can sign up and upload content as long as they follow the cadyou community guidelines. Uploaded content can be licensed under one of the Creative Commons licenses.