A day or so ago, Ben wrote an entry summarizing a thread at SEW Forums named Duplicate Content Penalty Timespan, where a member told others that he believes that there is a set time span dependent on the number of offenses for the length your pages will be penalized for duplicate content. Danny Sullivan just responded in the thread stating that he got word back from Matt Cutts of Google that this is not exactly the case. The exact words of the email was; "I mentioned concrete numbers, but as a "for example" illustration. It's not a 30-60-90 day thing."