Bob Lutz, the vice chairman of General Motors, does it. So does Jonathan Schwartz, chief operating officer of computer maker Sun Microsystems. A handful of executives at Hewlett-Packard and Boeing are also getting in on the act.

Welcome to the blogosphere - home to those informal, frequently updated online journals that people create to share their thoughts and opinions. Web logs, or blogs, have for the most part remained the domain of millions of independent bloggers who want to talk politics, trade tech ideas, share their daily lives - or criticise corporations.