Academia.edu is quite an interesting project – a tree of academics around the world.
Essentially the site creates the opportunity for members of any department in any university in the world to add thesmelves and their research interests onto the various branches of the tree. If your university is not on the tree you can add it.
Doesn't look super usable or exciting right now, ie., it's quite empty but some departments in some universities are pre-populated for individuals to claims as 'their listing' – but the transparency of the layout should make it quite easy to navigate and self-evident to newcomers. There are a bunch of big names on their to try to attract people – perhaps through appealing to their Erdos vanity – like Richard Dawkins and Stephen Hawking.