Interesting ruling by the 9th circuit this week... the feds can't prosecute medical pot users who use it on the advice of a physician and obtain the drug at no charge. Not just a decision for patients, also a decision that recognizes that the constitution does actually limit the Federal Government's power to control your life by taking away your ability to buy what you want or need. The feds had been relying on the infamously expanded Interstate Commerce clause to make what a local doctor was prescribing as medicine illegal. In this case, "the cultivation, possession and use of marijuana for medicinal purposes and not for exchange or distribution is not properly characterized as commercial or economic activity" and therefore not in the scope of Congress's power to regulate.
Link to ruling in PDF format.