There are many others and I haven't played with all of them. They also each have different weaknesses and strengths....but there's a start.
June 11, 2012
CVs for Scientists and Researchers in Sociology
In recent years, there's been a veritable explosion of tech related to education or otherwise targeted toward academics. For example, have a look at this article: Social Networks Proliferate for Academics Despite Some Doubts Some of the most popular sites include Academia.edu, Linked.in (not specific to academics, but academics find it useful), Twitter (again, not specifically targeting academics), Mendeley, citeulike, iAMscientist, VIVO web, Direct2Experts (more like a search engine) and just to add one more-- Cestagi.