Patexia has launched IP Research, "a patent search tool combined with advanced visualization features that provides focused and specific insights into IP-intensive industries." Presently in its beta release, Patexia’s “freemium” service provides an advanced patent search, visualization platform (free of charge).
Pedram Sameni, founder of Patexia, states, "we have also implemented a patent review section. As Patexia aims to be an online resource where industry professionals can market their expertise, we strive to empower businesses and individuals alike by allowing current members the ability to share their expert opinions on specific patents." This is also in beta release.
I did a quick tour of the IP Research tool and the video tutorial and it seems to offer some rich functionality for research. I have also added it to the Tools section in the left margin. Learn more here.