Directory of RSS Feeds
If you are old school like me and still prefer consuming online content through RSS feeds, this directory is for you.
Most of the popular online apps and services – including the likes of Facebook, YouTube and Twitter, offer RSS feeds but the problem is that you have to be a near geek in order to discover any of these feeds. Hence, I compiled this directory that will probably help you find XML feeds for your favorite online services without digging into the complex APIs.

  • YouTube RSS Feeds

youtube
1. Get the most recently uploaded videos of any YouTube user
https://gdata.youtube.com/feeds/api/users/<user>/uploads [example]

2. Get the RSS feed of videos that contain a particular tag
https://gdata.youtube.com/feeds/api/videos/-/<tag> [example]

3. Get the RSS feed for any search query on YouTube
https://gdata.youtube.com/feeds/api/videos?q=<query>&orderby=relevance [example]
Replace “relevance” by either “published” or “viewCount” to order search results by the upload date or view count of videos respectively. Also, here are some standard feeds for most shared YouTube videos, most highly rated videos, most viewed videos and so on.

  • Facebook RSS Feeds

Facebook
1. RSS feed of your Facebook Notifications
Go here to see the private link of your Facebook notifications feed.

2. Subscribe to Facebook Pages via RSS Feeds
https://www.facebook.com/feeds/page.php?format=atom10&id=<ID> [example]
To get the ID of any Facebook Page, go to graph.facebook.com and replace Digital Inspiration in the URL with the username of any Facebook Page. Also, Facebook does not offer RSS feeds for individual profiles.

  • Twitter RSS Feeds

Update: Twitter no longer supports RSS Feeds but you can still generate your own using this workaround.
twitter
1. Get the 20 most recent updates of any Twitter user 

https://api.twitter.com/1/statuses/user_timeline.rss?screen_name=<user>

2. Get the favorite tweets of any Twitter user 

https://api.twitter.com/1/favorites.rss?screen_name=<username>.rss

3. Get mentions of any Twitter user as an RSS Feed 

http://search.twitter.com/search.rss?q=to:@<username>

4. Get the RSS feed for any search query (or hashtags) on Twitter 

http://search.twitter.com/search.rss?q=<query>

5. Get the RSS feed of a Twitter List 

https://api.twitter.com/1/<username>/lists/<list-name>/statuses.atom
[Tip] If you wish to insert two or more words in your search query, use %20 as the separator – for example Hello%20World.

  • Pinterest RSS Feeds

Pinterest
1. Get the RSS feed of any Pinterest user
http://pinterest.com/<user>/feed.rss [example]

2. Get the RSS feed of any Pinterest board
http://pinterest.com/<user>/<board>/rss [example]
Pinterest, at this time, does not offer RSS feeds for search results though that would be extremely useful.

  • Image RSS Feeds for Instagram, Picasa and Flickr

Flickr
1. Get the RSS feed of photos uploaded by a Flickr user
http://api.flickr.com/services/feeds/photos_public.gne?id=<ID> [example]

2. RSS feed of Flickr photos that contain certain tags (comma separated)
http://api.flickr.com/services/feeds/photos_public.gne?tags=<t1>,<t2> [example]
Instagram
3. RSS Feeds of Instagram photos that have a particular tag
http://instagr.am/tags/<tag>/feed/recent.rss [example]

4. RSS Feeds of Picasa photos that match a search terms
http://photos.googleapis.com/data/feed/base/all?alt=rss&kind=photo&q=<search> [example]
If you know the username of a Flickr user, you can find his or her ID using this online tool (the ID format is 18436325@N00). Instagram does not offer RSS feeds for individual users officially but there are third-party Instagram viewers that can add the missing RSS feeds.

  • Blog Feeds for Tumblr, Blogger and WordPress

Blogs
1. Get the RSS feed of a Blogger (blogspot) blog
http://<blogname>.blogspot.com/rss.xml [example]

2. Get the RSS feed of a Tumblr blog
http://<blogname>.tumblr.com/rss [example]

3. Get the RSS feed of an WordPress hosted blog
http://<blogname>.wordpress.com/feed/ [example]

  • Private RSS Feeds

Here’s a list of popular web apps that offer private RSS feeds for your eyes only:
Dropbox – Enable RSS feeds under your Dropbox Settings. Then go here to get your unique feed URL that is useful for tracking changes to your Dropbox files and folders.
https://www.dropbox.com/123/456/789/events.xml [sample format]
InstaPaper – Open the Instapaper website, scroll to the bottom of the page and you’ll see an orange RSS icon pointing to the feed of your Instapaper bookmarks. changes to your Dropbox files and folders.
http://www.instapaper.com/rss/123/456 [sample format]
Foursquare – Go here to get a feed of all places where you have checked-in using Foursquare.
https://feeds.foursquare.com/history/ABCD.rss [sample format]
LinkedIn – Go here to enable your private feed that contains the activity of your LinkedIn network.
http://www.linkedin.com/rss/nus?key=abcdef [sample format]

  • RSS Feeds for Google Products

Gmail – Gmail offers Atom RSS feeds of your Inbox but it requires your password in plain text. The alternate is that you Gmail to Twitter (as a private user).
http://<username>:<password>@gmail.google.com/gmail/feed/atom/
Google Search – See how to create an RSS feed for Google Search using Google APIs.
https://www.googleapis.com/customsearch/v1?alt=atom&key=API_Key&q=<Query>
Google Finance – You can track news around stocks and currency via RSS Feeds.
http://www.google.com/finance/company_news?q=<Symbol>&output=rss [example]
Wikipedia – Track changes to any Wikipedia entry using an RSS feed.
http://en.wikipedia.org/w/index.php?action=history&feed=atom&title=<Page_Title> [example]
StumbleUpon – Get the RSS feed of likes of any SU user
http://rss.stumbleupon.com/user/<username>/favorites [example]
Evernote – Any shared notebook on Evernote can also be subscribed as an RSS feed.
https://www.evernote.com/pub/<username>/<notebook>/feed [example]

You can also use the RSS Search Engine at CtrlQ.org to discover more RSS feeds around your favorite topics (including podcasts).