A few approaches I'm currently using:

1) StumbleUpon

Once you create an account, add in some interests. These can be general (e.g. "Technology") or more specific (e.g. "User Interface").

Then, at the top of the page is a big dropdown that by default says "All Interests." Pop that open then poke on the interest you're looking to get ideas for.

Start stumbling and see what comes up.

2) Facebook

Create a new Facebook page for yourself. It doesn't need to be public.

Then, when on that page, open the "Edit Page" menu at top and choose the last item, "Use Facebook as PAGENAME."

Then, use search or whatever means to find pages that post like-minded content to what you're looking for and "Like" these pages. {NOTE: Because you are "acting as" your page, YOU are NOT liking these pages, your page is liking them.}

Okay, so now you should have a page that you're acting as, and you've liked some other pages.

Now if you go to the FB homepage, you'll see a custom newsfeed of posts from JUST those pages that you liked (plus ads).

Over on the left (in today's interface at least) there's a little arrow next to Newsfeed. Click that and switch to most recent.

Voila, the freshests posts from the pages you like.

You can switch back to "Use Facebook as YOURNAME" using the arrow at the very top right of the desktop interface.

3) Sharegrab.com

This is from the EdgeRank Checker people. Basically, you log in and create Pods (read: groups or lists) of FB pages.

Then, you can choose a pod, and a date range, and it'll show you the most "shareworthy" posts from those pages.

Hope this is helpful. Please feel free to reach out to me if you need any assistance implementing these ideas, or creating a custom blended RSS feed (which is still a fantastic way to achieve your goal).

https://clarity.fm/toddlevy