Social Media at the Forefront of HR Innovation

Most organizations use social media in their recruiting and marketing efforts but many organizations are beginning to use social media as a way to enhance and transform the way talent is managed, engaged, and developed. In fact, according to recent data as many as three quarters of HR heads are planning on increasing their social media spend. How can social media be used to enhance networking in distributed, global organizations?
Can internal blogs and wikis improve learning and development? Will performance reviews become more like Yelp ratings? More importantly, how can this technology enable HR to execute strategy more effectively and contribute to the bottom line?