Corporate blogs with meaning

Many corporations successfully employ the use of blogs, not just as a PR or media promotional tool, but for actual dialogue with their customers. Sometimes that dialogue actually generates content for the company, such as the data uploads in the Nike plus blog, or just give a down to earth voice to the company during rough times.
For Example...

Nikerunning.Nike.com
The blog serves as a central blog and data-upload point for users of the Nike+ running sensors made for use with iPod and iPhone products. It is administered by Nike, but allows customers to upload rubbing statisics, plan group events, and issue "Challenges," a publically-listed competition where, for example, runners can share their data to become the first person to "Run 500 Miles in 2010" (currently with 12,639 CHALLENGERS).
This serves as a great tool for Nike to foster a sense of community and develop an active communication betwee designers and the people most devoted to their products.

General Motors "Fastlane" blog

This blog serves as a hobby horse for Bob Lutz, the vice-chairman of the troubled car company, as well as a forum for classic car lovers to share, comment, and show off classic GM cars, and upcoming exclusive pictures of cars that haven't hit the road yet. Dome people have questioned the company haveing such a direct mode of communication, but in Lutz's own words:
"I will continue to do it, whenever I can, and as long as it seems people want to read it. And by the way, GM thinks its blogs are a success, too, and will forge ahead with all of them."