If you are running Office 2003, please install service pack 3 NOW.  If you are hesitant, I encourage you to please . . . think of the kittens.
Here's the download URL: http://www.microsoft.com/downloads/details.aspx?FamilyId=E25B7049-3E13-433B-B9D2-5E3C1132F206&displaylang=en (you should also just be able to scan your system with Microsoft Update or Office Update).

Here's what others are saying: http://blogs.pcworld.com/staffblog/archives/005444.html

We'll apparently have a support webcast - you can learn more about it here: http://support.microsoft.com/default.aspx?kbid=941396

I can't stress enough how huge or important this update is for Office 2003.  This is, if nothing else - a very large security update for Office 2003. :)