RSS is a powerful feature of websites. It allows a very easy integration with websites, allowing software, or other websites to pull information from a website. When used properly it can be an extremely powerful tool for access information. Look for this 
icon on websites or in your browser to indicate that an RSS feed is available for your current website. However you won’t find this on many Social Media websites. They are well hidden, but they do exist you just have to know how to get to them. So today I present them to you.
Pinterest RSS
A user’s RSS feed can be accessed by going to the user’s Pinterest URL then adding /feed.rss to it.
Example: http://pinterest.com/ghostprogrammer RSS Feed: http://pinterest.com/ghostprogrammer/feed.rss
A board’s RSS feed can be access by going to the board’s Pinterest URL then removing the ending / and replacing with .rss
Example: http://pinterest.com/ghostprogrammer/technology-that-i-love/ RSS Feed: http://pinterest.com/ghostprogrammer/technology-that-i-love.rss
Twitter RSS
To access a user’s RSS feed of tweets, can be accessed by using the following URL and appending the user’s name: http://api.twitter.com/1/statuses/user_timeline.rss?screen_name=
Example: http://api.twitter.com/1/statuses/user_timeline.rss?screen_name=ghostprogrammer
To access a RSS feed for searching a tag, can be access by using the following URL an appending the tag: http://search.twitter.com/search.rss?q=
Example: http://search.twitter.com/search.rss?q=fccparisky
To access any mentions of a users in an RSS feed, can be accessed by using the following URL an appending the tag: http://search.twitter.com/search.rss?q=to:@
Example: http://search.twitter.com/search.rss?q=to:@ghostprogrammer
Foursquare RSS
Look in the bottom right hand corner of your history page to find the RSS/ICS/KML link. This will lead you to a page that will exapling the RSS feeds available. These links will contain a a secret key that should remain private, anyone with access to this key has access to all of your present and historical check-ins. You can reset this key from this same page if you think it has been compromised.