HARO | Social media kitbag | Scoop.it
Not tried this myself, although I have just registered. This was suggested by someone on Quora.

From the site's blurb: For reporters "Tap into the largest source repository in the world with over 80,000 mainstreet and expert sources who will respond directly to your query on your terms. No more flipping through your rolodex; searching out-of-date databases, or being bothered by unsolicited sources with off-topic pitches. Submit your query and let HARO deliver the perfect sources right to your inbox. "

And for sources: "From The New York Times, to ABC News, to HuffingtonPost.com and everyone in between, nearly 30,000 members of the media have quoted HARO sources in their stories. Everyone’s an expert at something. Sharing your expertise may land you that big media opportunity you’ve been looking for."

Please add your comments or experience of using this tool in the box below so everyone can benefit.