There is some pretty decent science-based information compiled by the California Society of Addiction Medicine available here.

We put up a blog post last May that builds off an excellent AP piece analyzing what the War on Drugs has cost the U.S. since it was launched forty years ago, and how the Office of National Drug Control Policy has doctored its books (including a link to the FY2010 budget) to downplay the disparity between the federal dollars spent on failed law enforcement strategies versus the dollars spent on treatment and prevention.

The answer depends on whether you think whole-plant cannabis should continue to be treated as a controlled substance, like prescription medications, or instead primarily as an herb that has both medicinal and intoxicant uses.  If the latter, there's no reason to reschedule it - you could remove it from the federal Controlled Substances Act altogether and place it under different regulatory controls, perhaps like legal intoxicants or herbal remedies.

The legal mechanics of rescheduling (to, say, Schedule II, III, or IV), and the U.S. history of attempts, are covered pretty well here.  Politically, one would want to continue to build the science base around the medical benefits and actual (versus imagined or exaggerated) potential for harm, which the federal government has made extremely difficult through its stifling of research into the therapeutic uses of cannabis.

Removing whole-plant cannabis from the Controlled Substances Act altogether ultimately has to happen at both the federal and international level (due to treaty obligations), but needs to start with the states.  Congress is not likely to move until states push them to do so.

To move the states, you have to move the people - and not just the people who are already with you.  Sen. Jeanne Kohl-Welles's introduction of SB 5615 and Rep. Dave Upthegrove's introduction of HB 1177 in the Washington state legislature in 2009; Rep. Mary Lou Dickerson's introduction of HB 2401 in 2010; and Rep. Dickerson's introduction of HB 1550 in 2011 all provide great examples of how to move a state's conversation around cannabis law reform from the choir to the mainstream: see Exhibit A, B, C, D, E, F, G, and H.  Creating a space for dialogue that is free of both the Reefer Madness and Cheech & Chong stereotypes allows us to engage a broader audience in a serious discussion about whether a new approach to cannabis - one based on a public health model rather than prohibition and criminalization - might serve our communities better.

Once you've engaged people in talking about the possibility of a new approach, you can start to hammer out the details of what that new approach might look like.  And then you can ask them to vote it into law.

The proposal might meet a court challenge, but until a state's legislature or voters demonstrate the political will to try something new, Congress will not be moved to change federal law to allow the experiment to proceed.

The state Board of Pharmacy has the authority to schedule and reschedule controlled substances under RCW 69.50.201. The state legislature could also reschedule by amending the Uniform Controlled Substances Act to remove marijuana from Washington's Schedule I.

The problem is that until the federal government - through either the Drug Enforcement Administration (DEA) or Congress - reschedules marijuana within the federal Controlled Substances Act, rescheduling at the state level serves little purpose. This is because the ability to prescribe controlled substances is controlled by the federal government through DEA registration. If the DEA believes a prescriber "has committed such acts as would render his [or her] registration ... inconsistent with the public interest" (by, say, prescribing marijuana), the agency can initiate proceedings to revoke his or her DEA registration.  This would prevent the medical professional from prescribing medications and thereby make it difficult to continue practicing medicine.

This is exactly the tactic taken by the federal government when California passed our nation's first medical marijuana law in 1996.  The feds threatened the DEA registration of any California doctor who recommended marijuana in compliance with state law.  The ACLU sued and won an injunction.  The distinction between a prescription and a medical marijuana recommendation was key to the decision:

On appeal, the government first argues that the "recommendation" ... is analogous to a "prescription" of a controlled substance, which federal law clearly bars.  ...  If, in making the recommendation, the physician intends for the patient to use it as a means for a patient to obtain a controlled substance, then a physician would be guilty of aiding and abetting the violation of federal law.

Conant v. Walters, 309 F.3d 629, 635 (9th Cir. 2002).

Federal control of the ability to prescribe is why Oregon's rescheduling of marijuana last summer had no effect on practitioners' ability to prescribe it.

Tough question.   You've identified indirect costs that aren't easily quantified - the hardships to families resulting from a breadwinner being locked up or saddled with a criminal record , e.g. - which can translate to additional burdens on taxpayers.  On the other side of the coin, estimating revenues necessarily entails rough approximations of how the price of cannabis, and usage rates, would be impacted by bringing it under the control of a regulated market.

How many taxes are collected, and where they are funneled, is also a question of legislative drafting.  For example, last session's HB 2401 , which would have regulated the cannabis market through the Liquor Control Board , proposed imposing a tax of 15 percent per gram .  It also would have created a "marijuana revolving account," with 98 percent of LCB revenues going to the Washington State Department of Social & Health Services' Division of Behavioral and Health Recovery for substance abuse treatment and prevention .  The remaining 2 percent would be retained by LCB for administrative costs.

But we do have some figures to consider that come straight from Washington state agencies.

According to the fiscal note for HB 2401:

Revenues

The Department of Revenue (state general fund) would receive roughly $46 million in the first year , increasing to $61 million in FY2019.

The Liquor Control Board would receive $140 million in the first year , with 98 percent of that of that going to the marijuana revolving account for substance abuse treatment and prevention services , increasing to $173 million in FY2019.

Savings

Cities and counties would save $2,655 in court, prosecution, defense, and jail costs per each misdemeanor possession case not charged, for a potential minimal savings of $11,774,925 annually , based on the 4,435 misdmeanor possession cases that resulted in conviction in 2009.  However, there were likely an additional 8,000 cases filed in court in 2009 that didn't result in conviction .  There were 12,428 misdemeanor pot cases filed in Washington courts in 2008.  Cases that don't result in conviction still require prosecution, defense and court time - and can include jail time from an initial booking - so it's not unreasonable to estimate that annual savings could be closer to $20 million.

Cities, counties, and the Washington State Patrol save $375 in officer time for each adult misdemeanor marijuana arrest that doesn't happen.  The fiscal note for HB 2401 identifies 8,273 of these in 2008, for a grand total of $3,102,375 in annual savings .

Counties would save $7 million annually in prosecution, defense, and jail costs associated with the 700 marijuana-related felony sentences imposed in FY08.

Roughly $1.5 million per year in state general fund savings would result from the Department of Corrections not seeing those 700 felony convictions, and another $222,700 per year from the Washington State Patrol Crime Lab not analyzing the pot in those cases.

It's difficult to know because the only organization I've heard of conducting annual surveys on drug testing in the private sector, the American Management Association , appears not to be conducting them anymore - or at least not making them publicly accessible.

According to the U.S. Department of Labor, the AMA has reported in the past that "workplace drug testing has increased by more than 1,200 percent since 1987.  More than 81 percent of businesses surveyed in 1996 were conducting some form of applicant or employee drug testing.  Likewise, the perceived effectiveness of drug testing, as assessed by human resources managers, has increased from 50 percent in 1987 to 90 percent in 1996."

To learn why drug testing is a bad investment for employers, check out this ACLU report .

To learn about how drug testing is resulting in employees with terminal and debiliating conditions getting fired for no reason other than their physician-authorized medical use of cannabis, read this CNBC article published today.

In 2006, Congress passed the Higher Education Reconciliation Act of 2005 ("HERA"), which limited application of the federal financial aid penalty to students who were receiving aid at the time of the commission of the "offense."

A student who is enrolled on the date of the offense and receiving federal financial aid for that period of enrollment becomes ineligible to receive aid for one year on a first offense, two years for a second offense, and indefinitely for a third.  20 U.S.C. sec. 1091(r) .

You can learn more about ongoing efforts to repeal this law altogether here .

You didn't mention whether your doctor had issued you an authorization to engage in the medical use of cannabis.  If not, requesting that should be the first thing you do.

Your doctor's advice not to smoke is sound: vaporization is better for the lungs, especially if you are a regular user.

If you are questioned by law enforcement, the following four rules apply, regardless of the basis for the questioning:

1. Be polite.

2. Don't admit OR DENY anything. Exercise your constitutional right not to answer questions. Anything that is not exercised atrophies.

3. Politely ask whether you are under arrest. If you are not under arrest, let the officer know that you would like to be on your way, and then be on your way.

4. If you are arrested, request your right to talk to a lawyer, and otherwise exercise your right to remain silent.

One caveat: the Washington State Medical Use of Marijuana Act requires, if you want to be able to raise the medical marijuana defense at trial, that you present your authorization and identification to any law enforcement officer who inquires about your medical use of marijuana. So, if you are a qualifying patient, present your ID and paperwork when asked.

With respect to non-medical use of cannabis, I can't provide better advice than Jeff Steinborn.

Off the top of my head, I'm not aware of any studies that answer your questions, but I can suggest you check out Erowid, www.erowid.org. I have consistently found them to be a good source of consumer-focused information.