Scott Monty gives a few direct hints on how corporations should engage in social media:

"Don't think of social media as a campaign. It's commitment."
"If your customers are there, you need to be there too."
"You need to spend time listening."
"It gives you a chance to create value for them."
"You need senior leadership support."

Ford's social media efforts from JD Lasica on Vimeo.

Inspired by article on socialmediabiz.com.