You have probably already heard of this but I wanted to send it out anyway.

10 May 2000 Email viruses are now spreading WITHOUT THE USER
OPENING ANY ATTACHMENT.
Personal computers running Internet Explorer (IE) version 5.0 and/or
Microsoft Office 2000 are vulnerable to virus attacks using most email
systems, even if the email recipient opens no attachments. You don't
even have to use IE; just have it installed with the default security
settings. If you have not closed the hole, you can receive viruses (and
spread them) by viewing or previewing malicious email without opening
any attachment, or by visiting a malicious web site. The problem is
caused by a programming bug in an Internet Explorer ActiveX control
called scriptlet.typelib. This is by far the fastest growing virus
distribution problem and ripe for a hugely destructive event - at least
as large as the ILOVEYOU virus. Updating your virus detection software,
while important, is not an effective solution for this problem. You must
also close the hole. The hole can be closed in five minutes or less
using tools available at Microsoft's security site:
http://www.microsoft.com/security/bulletins/ms99-032.asp
The correction script may be run directly from:
http://www.microsoft.com/msdownload/iebuild/scriptlet/en/scriptlet.htm