Imagine walking into a coffee shop, corner market or any grocery store with a state-approved cannabis licenseand buying a joint or an ounce of pot, plus tax.

Or imagine growing marijuana in a fenced backyard without fear of arrest.

Gov. Arnold Schwarzenegger's surprise call last week to debate legalizing adult use of marijuana in California has drawn international attention, shifting the prospect of such a change from the fringe to the forefront.

Advocates of legalization, including state Assemblyman Tom Ammiano of San Francisco, whose legislation caught the governor's attention, have created a concept for a system of regulation and taxation that would make the state's marijuana laws among the most liberal in the world.

"Suddenly this is all open to discussion," said Oakland attorney James Anthony, who handles land-use and zoning issues for medical marijuana dispensaries in the state. "When somebody as conservative and cautious as the governor says it's time to debate ... then we're in a very different context."

California, in 1996, became the nation's first state to legalize marijuana for medical use, creating a multimillion-dollar industry and scores of dispensaries where residents buy marijuana with a physician's approval.

Ammiano's proposal, at the least, would allow personal possession and cultivation of as many as 10 plants.

But if the decades-long federal ban on possessing, growing and selling marijuana were repealed, the state law would legalize pot for adults over 21 years old, create a regulatory system and impose a $50-an-ounce sales tax on marijuana, much like taxes on tobacco and alcohol.

Packaged marijuana would be sold from a locked cabinet behind the counter, similar to hard liquor, under the proposal.

The state Board of Equalization, which collects sales and use taxes, expects cannabis prices would drop, use would increase and the state would take in $1.3 billion annually in the fees. The agency estimates that sales of marijuana for medical use now generate $18 million a year in taxes.

Ammiano said the state has a history of bucking federal government regulations with its own, and he thinks the Obama administration may be open to reforming federal marijuana-enforcement laws.

Where could pot be sold?

He has yet to ask for anyone to co-sponsor the legislation, which he plans to move at a deliberate pace over two years. But if federal laws were changed, Ammiano's proposal would present intriguing and banal policy questions:

-- Would it be regulated by a state agency, such as the state Alcoholic Beverage Control department, or would local jurisdictions have that power?

-- What zoning issues would a cannabis license be subject to?

-- Could local jurisdictions ban the licenses outright - resulting in "dry" areas?

-- Where marijuana could be sold, whether in specialty stores or everywhere alcohol and tobacco are sold, would also create intense debate. Would the speciality stores be run by the state, like liquor stores in Idaho and Oregon, or by private citizens?

'Coffee-shop model'

Richard Lee, president of Oaksterdam University in Oakland, a marijuana dispensary and education group, said he prefers allowing pot sales only in cafes, as is done in Amsterdam.

"I like the coffee-shop model," Lee said. "I think it goes well together, like a restaurant that serves alcohol that goes well with a meal."

Lee said he doubts Schwarzenegger would sign the legislation in its current form, given that the governor has vetoed laws legalizing the growth of industrial hemp and barring employers from firing workers who use marijuana.

Initiative in the works

But he said marijuana advocates are working on a statewide initiative to carry out the goals of Ammiano's legislation and allow voters to bypass the Legislature as they did in 1996, with Proposition 215, which legalized the use of marijuana with a doctor's permission.

A spokesman for the federal Drug Enforcement Administration said debate over the effects of legalization is good. But he thinks most people ultimately would side with the status quo.

"I think there are very simplistic catch phrases put out there," spokesman Garrison Courtney said. "This is a complex issue and there does need to be discussion about it. But the thing is, it's not like there hasn't been discussion."

Feds say crime a problem

He doubted that legalization would push drug cartels out of the state and said the argument that legalization would reduce violence is just "scratching the surface."

It's questionable, he said, whether estimated tax revenues would be offset by the costs of regulation and addiction treatment.

Marijuana advocates challenge those assertions and are ready for debate, too. Oakland attorney Bill Panzer, who helped draft Prop. 215, says the state should move ahead without consent from the federal government.

"My feeling is the more you put it in the feds' faces, the more of a chance you have of actually getting somewhere," Panzer said.