[buboard]

I vote against fist bumps and in favor of leg or butt bumps. (Highly unlikely to scratch your face with your butt )

[praptak]

Also elbow bump, aka "the Ebola handshake".

[downerending]

I think Netanyahu (sp?) just recommended the Indian "namaste" greeting (put your hands together and nod). Excellent idea.

[em-bee]

but you scratch both with your hands