Microsoft has just released a patch for the WMF vulnerability.. which is very serious.. any website that showed you an image could infect your computer directly (If you use IE), or very quickly (if you use firefox, it asks you to open the image). This also isn't something that may be detected by your antivirus, as new varients are released very quickly.
You can get the patch at
http://www.microsoft.com/technet/sec.../ms06-001.mspx
Just a reminder to patch.. its pretty important to do it with this one.