Realogy Corp. franchisor Coldwell Banker Real Estate LLC is inviting visitors to coldwellbanker.com to mine listings photos and create theme-based picture collages of their favorite home features on Pinterest.Each listings detail page on coldwellbanker.com invites users to "like" the home on Facebook, share it on Google Plus, or "pin it" on Pinterest.A 19,500-square-foot mansion on the market for $18.5 million in Reno, Nev., for example, has been pinned more than a dozen times (the "pin it" button will soon be added to the Coldwell Banker Previews International website).To demonstrate the possibilities of Pinterest, Coldwell Banker has created its own page on the social media site. As of today, Coldwell Banker's Pinterest account, managed by Lindsay Listanski,...