These days most of the viruses are transmitted by the use of Pen Drive. You get plenty of viruses and worms and most of they work through autorun program.
If you could kill the autorun viruses when you insert your pen drive in you computer you may never get any viruses or worms in you computer from any pen drive or flash drives.
The best solution is to run a Autorun Killer (Antiautorun) which would be your best companion.
download.thaiware.com
or
Download >> CPE17 Autorun
or Download from the attachment