What is Researchgate? Well, it's a social media like Academia.edu and Mendeley.
Here is a link to my profile: http://www.researchgate.net/profile/Meagan_Arrastia
This site creates a metrics based on the number of publications, citation, and activity in the research online.
Just like Diginole, you have to be careful about sharing published works. On the site you should only upload pre-press versions of your work. Like Slide Share, you can share presentation slides. What is different is that it provides a question and answer area where you an consult experts directly.
Have you used this site? Share your links here.