I'm increasingly seeing anti-malware products that either automatically scan USB drives on insertion or that offer to do so.
It has just come to my attention that Didier Stevens has written a script that can launch a program (like an virus scanner) when a USB drive is plugged in. So if you want this feature, your anti-virus doesn't have it and you use Windows then USBVirusScan is one solution.
USBVirusScan was first created around five years ago. That is how up to date I am.