If you haven't heard about the Conficker worm, you must have been in hiding, but just a reminder. Speculation is that the worm, which may be present on millions of Windows computers, will get activation instructions April 1. No one is sure what it will do, if anything. But you should make sure you have the latest updates for your operating system and security programs. Don't assume that automatic updates has taken care of it, because one thing that Conficker C does is turn off automatic updates. Backing up your data before tomorrow (April 1) also might be a good idea.
For anyone interested in more detail about Conficker, here is a link to the advisory from the U.S. Computer Emergency Readiness Team.