Katieq, Clarity is the name of a control in Adobe Camera Raw. The control adds sharpness by adjusting edge contrast. The control’s effect is adjusted via a slider in the controls panel.
Another couple that I think of when seeing some photos on the page you linked, that also do much better work, are Andrzej Dragan (http://www.andrzejdragan.com/) and Joel Grimes (http://joelgrimes.com/GalleryMain.asp?GalleryID=24128&AKey=P7FJP8B4)
There is a article that describes a processing method here: http://www.dmimaging.net/photography-trends-dragan-effect/