Those who are used to using or consulting delicious.com, blinklist.com, faves.com, etc. They are quite clear about the concept of social bookmarking, places where people share links and the most popular ones are highlighted. Here I want to show you a list of these types of applications that are not usually within the great myths, such as those mentioned above, and can be useful for searches of certain topics.
– bibsonomy.org: Links related to literature. Any user can share the publications of various types found on the Internet, allowing their classified distribution.
– citeulike.org: With articles and links related to the educational and professional environment. The content is classified by groups, allowing you to discover very specific content about each area.
– connotea.org: With links for researchers and scientists. A very active and professional community.
– kaboodle.com: With products that users find in online stores around the world. We could define it as a delicious consumption.
– mobleo.net: A social bookmarking site specially designed for mobile phones.
In short, there are hundreds of options, of which I have indicated some that, personally, I use in my day to day to, among other things, find content that I can share with you.