Yesterday we offered up a guide to protecting your Windows PC from the Conficker worm, set to start doing ... something today. Free net service OpenDNS is another option for anyone concerned about today's not-so-funny happening. Why? OpenDNS has been tracking the Conficker worm and blocking the sites it keeps reaching out to for its nefarious further instructions. As OpenDNS' David Ulevitch puts it: The latest variant of Conficker is now churning through 50,000 domains per day in an attempt to thwart blocking attempts. Consider this: at any given time we have filters that hold well over 1,000,000 domains (when you combine our phishing and domain tagging filters). 50,000 domains a day isn't going to rock the boat. In other words, even if Conficker has made it onto your PC, or a PC somewhere in your house/office, OpenDNS will likely stop the worm from contacting the site that would tell it what to do. If you're still using your Road Runner/Comcast/Verizon DNS pre-sets on your home...