Shortly after group buying company Groupon Inc. and Angie’s List Inc., San Francisco-based Yelp! has filed with the U.S. Securities and Exchange Commission for an 2012 initial public offering (IPO) of up to US$100 million. Yelp, a site featuring user reviews of restaurants and businesses,... [[ This is a content summary only. Visit my website for full links, other content, and more! ]]