It become a default assumption in all new web applications (that I have worked on or read about) to have an integration with either facebook, twitter, linked in, or all the three.

Working with these on rails is no longer rocket science as the various plug-in and gems do most of the work for us. I thought it would be appropriate to create a place for my reference as well as that of others to collect some good tutorials that allow us to do these integrations.  To start off, I am adding a few good ones that I have referred to or those that have a lucid explanation and are a good read.

Facebook

• restful_authentication for facebook (by Stuart Eccles)
• facebook’s page explaining methods to integrate Rails projects with the Facebook platform

Twitter

• oAuth authentication for twitter (by Avand Amiri)
• list of oAuth examples in various languages @ twitter.com

Linked In

• oAuth integration for LinkedIn with the twitter gem (by Wynn Netherland)
• alternative to oAuth to authenticate with LinkedIn (by Paul Lindner)

Hope this helps and do comment with more such tutorials that you find on these social networking integrations. I’ll keep adding to this list as and when I find good new tutorials.