If you are still coming to terms with Web 2.0 and Social Media check out these great online slide resources...

What is social media? and The evolution of communication

Social media metrics

What should companies be doing? Taking at least 10% of their customer services, PR and marketing budgets and putting them 'on (the) line' to engage in the ongoing conversation. Ensuring all employees are fully up to speed on using social media (infact many are already doing so) to improve internal and external communications.