SAN FRANCISCO - The biggest hit on the medical marijuana scene could soon be a high-tech gizmo that lets people inhale the drug but skip the smoke.

The device is a marijuana vaporizer. One version looks like a metallic volcano and sells for more than $500. Its creator calls it "the Mercedes-Benz of vaporizers."

By heating marijuana to a point where vapors are formed but before combustion, a vaporizer is free of many of the toxins found in marijuana smoke, advocates say.

"You don't have the harshness you get from smoking, no next-morning cough, no shortness of breath," said Kathy Gagne, a 56-year-old Oakland resident who began vaporizing marijuana five years ago to treat her depression.

The Bay Area has apparently become the hub of the vaporization movement - from a just-completed UC-San Francisco study on the technology's effectiveness to Alameda County officials' plans to allow the devices in new marijuana dispensaries.

More than a dozen manufacturers have sprung up to churn out the devices.

But federal officials aren't fired up about the vaporizers - or what they deliver.

"Until an application ... is approved by the Food and Drug Administration, marijuana will continue to be classified as a Schedule I (illegal) drug," sniffed Jennifer Devallance, spokeswoman for the Office of National Drug Control Policy.