Dan Gillmor reports on the latest company to make a mistake on its blogging policy: Hewlett-Packard. But the outcome is positive. After deleting a negative blog comment from a reader, the company reinstates it, saying it was a "good learning experience."

Gillmor, the Batman-like guard of open conversation, also covers another screw-up: The Churchill Club held a San Francisco event about changes in digital entertainment, and barred the professional media -- somehow forgetting the fact that anyone in the audience could blog freely about the event. We're waiting for word from investor Roger McNamee and Firefox's Blake Ross, who were on the panel, and both have blogs...