Google is currently in talks to acquire popular social review site Yelp for $500-million. The site was originally launched in 2004 and was “founded by Stoppelman and Russel Simmons with a $1 million investment from Max Levchin.” Continue reading to see the company’s innovative augmented reality iPhone app. Yelp lets users post ratings of up to five stars on businesses and give written reviews. More than 26 million people visit the San Francisco-based site monthly, and at least 8 million users post reviews, Ichinose said. [via Bloomberg]