Web 2.0 is about gathering Collective Intelligence.
I was looking at Fortune companies use of blogging and if they encourage their employees to blog.
Below are my picks (based on frequency of posts, page rank and content) – not listed by preference:
Tibco: http://tibcoblogs.com
GE Global Research: From Edison’s Desk
Sun Microsystems: blogs.sun.com
IBM: http://www-128.ibm.com/developerworks/blogs/
Oracle: http://blogs.oracle.com/
Google: http://googleblog.blogspot.com/
HP: The Digital Mindset
Cisco: The Platform: [...]

