Here are a few articles that sparked interest in the Internet marketing community over the last week.
Seems there were a slew of anti-Google articles written in the last week or so. Mostly retaliation on the Panda update and how some sites were wrongly penalized even though they followed Google’s guidelines of "original content". This is related to AdWords so now this issue is seeping into the realm of PPC as well.
Other PPC related articles.
Matt Cutts Video on the use of rel=canonical tag versus when to use 301 redirects.