K2 - Spice

I am so out of the loop. I didn't even know there was synthetic marijuana and now I am reading that its getting banned in state after state throughout the country.

From Wikipedia:

A large and complex variety of synthetic cannabinoids, most often cannabicyclohexanol, JWH-018, JWH-073, or HU-210, are used in an attempt to avoid the laws which make cannabis illegal, making synthetic cannabis a designer drug.

Seattlepi: State bans synthetic marijuana

Often called "K2" or "Spice," synthetic marijuana is a mix of common herbs sprayed with chemicals that mimic the high of pot. It is often sold as incense with a disclaimer that is it "not for human consumption." But users smoke it the same way they do cannabis.