WUPHF.com is a fictional website and social tool developed by Ryan Howard, but stolen from his then-girlfriend Kelly Kapoor. It is first seen in the episode Whistleblower, but is referenced numerous times after that.
According to Ryan in a deleted scene, WUPHF.com used to be a prototype. When the beta was launched in August 2010, the response had been incredible. WUPHF itself is pronounced "woof".