Source: Shutterstock Valuable Information flies across our attention dashboards at blinding speeds. As 2009 comes to a close and we embrace a new optimism for 2010, let’s revisit some of the most read and shared posts this year. Greatest Hits of 2009, Part IV: 1. Social Media is Rife with Experts but Starved of Authorities 2. Unveiling the New Influencers 3. PR Does Not Stand for Press Release: Equalizing Spikes and Valleys 4. The Decline of Traditional Advertising and the…