A recently-approved Michigan law allows patients with HIV, AIDS, cancer, glaucoma and other diseases to use marijuana for medicinal purposes on a doctor’s recommendation. Once registered with the state, qualifying patients will receive ID cards, which will allow them to legally acquire, possess, transport and even grow up to  2.5 ounces of marijuana. But, possession of marijuana will not be legalized for medicinal purposes until the Department of Community Health introduces application and fee guidelines. The expected date for these guidelines is April 4, 2009. Until then, anyone possessing marijuana – for any purpose – can be arrested and prosecuted. However, the new law allows patients to use a medical-justification defense at trial.