Via Slate, I see that the NY Times reports here that the World Health Organization is promoting elbow bumping as the infection-free alternative greeting.
The article says in part:
"The bump, a simple touching of elbows, is a substitute for the filthy practice of shaking hands, in which a person who has politely sneezed into a palm then passes a virus to other hands, whose owners then put a finger in an eye or a pen in a mouth. The bump breaks that chain. Only a contortionist can sneeze on his elbow."