Here is a good link to know : Internet Storm Center - it leads to a security site which has important information about current threats.

Right now, it says :

Forgery FBI email around

A false email from FBI with the Subject: "Your IP was logged" is being around with a malware in attachment.
The email intends to intimidate the user saying that the machine was scanned by the FBI and that
Illegal contents were found. The email will try to induce the user to check the attachment to see what
illegal contents were found.

Reference:
http://www.theage.com.au/articles/2004/01/06/1073268005348.html

Among other things.

This is another virus going around - don't be fooled!

There are also viruses that pretend to be gifts from paypal, auction wins from ebay, and warnings about other trojans/viruses (with convenient attached fixit programs, of course).

Let's be careful out there!