You still have to open an email attachment to be infected, right?
No.
Even thinking about it will trigger it!
just kidding....
LVM
http://www.datafellows.com/v-descs/mydoom_bb.shtml
http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?VName=WORM_MYDOOM.BB
http://www.us-cert.gov/other_sources/viruses.html#III
If you already got it, cleanup when your virus software supplier releases a "patch". A disconnected USB hard drive that contains your vital files(backed up regularly) can be very useful if a nasty one starts munching on your PC.