My favorite go-to spot for finding RSS feeds around a particular topic would have to be http://ctrlq.org/rss/ because of the ease of use and infinite combinations of searches which can be made.
For example, if you plug in something like the following, you'll get the most popular Tags for your videos:
Find the most popular Photo tags in your network by plugging in the following:
Instructions for Finding the Best Feeds
First: Preview the Feed
Second: Right Click and Copy Feed URL > Paste it into RSS Module
/* This is a great way to create a quick digest for a broadcast. Just copy and paste the results from PREVIEW RSS into your message/*
Other Workarounds for Finding RSS Feeds
Finding RSS Feeds for 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]
Amit of Digital Inspiration suggests:
Replace “relevance” by either “published” or “viewCount” to order search results by the upload date or view count of videos respectively. Also, here are somestandard feeds for most shared YouTube videos, most highly rated videos, most viewed videos and so on.
Finding RSS Feeds for 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.
Finding RSS Feeds for Twitter
Twitter no longer supports RSS Feeds but you can still generate your own using this workaround. If you wish to insert two or more words in your search query, use %20 as the separator – for example Hello%20World.
Finding RSS Feeds for Pinterest
Finding RSS Feeds for Instagram, Picasa, 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]
Tumblr, Blogger and Wordpress
Closing Tip: You never want to import a feed into your home page as it will encourage visitors to click off your site..place feeds for external sources in interior pages
I also have close to 60 other Ning tips for RSS feeds, so take a look!
If you are looking for someone with years of experience with Ning to help you set up your network for primetime, get in touch with me. Happy to help! Good Luck Ning Creators!