When creating rules in Entourage 2008, you can save some time by selecting a message like those you want the rule to work on before defining the rule. That way, when you add criteria to your rule, Entourage fills in the data based on the data in the selected message. So if you wanted to filter messages containing TidBITS, you could select an issue and add a new "From Contains" criterion to a rule. Entourage will automatically fill in the firstname.lastname@example.org address in the criterion.
From Adam C. Engst