Great little trojan/virus tool that will fit on a floppy disk....
http://vil.nai.com/vil/stinger/

Scans for the following as of Nov 22, 2005:

BackDoor-AQ
BackDoor-ALI
BackDoor-CEB
BackDoor-JZ
Bat/Mumu.worm
Downloader-DN.a
Exploit-DcomRpc
Exploit-LSASS
Exploit-MS04-011
HideWindow
IPCScan
IRC/Flood.ap.dr
IRC/Flood.bi.dr
IRC/Flood.cd
NTServiceLoader
ProcKill
PWS-Narod
PWS-Sincom.dll
W32/Anig.worm
W32/Bagle@MM
W32/Blaster.worm (Lovsan)
W32/Bropia.worm
W32/BuGBear@MM
W32/Deborm.worm.gen
W32/Doomjuice.worm
W32/Dumaru
W32/Elkern.cav
W32/Fizzer.gen@MM
W32/FunLove
W32/IRCbot.worm
W32/Klez
W32/Korgo.worm
W32/Lirva
W32/Lovgate
W32/Mimail
W32/MoFei.worm
W32/Mumu.b.worm
W32/MyDoom
W32/Nachi.worm
W32/Netsky
W32/Nimda
W32/Pate
W32/Polybot
W32/Sasser.worm
W32/Sdbot.worm.gen
W32/SirCam@MM
W32/Sober
W32/Sobig
W32/SQLSlammer.worm
W32/Swen@MM
W32/Yaha@MM
W32/Zafi
W32/Zindos.worm
W32/Zotob.worm