Hemp, or Cannabis, has many uses: ethanol or biodisel production (and can be further refined into a gasoline replacement), clothing, paper pulp, rope, hemcrete, insulation, it provides a hypoallergenic (making it better than soy!) vegan protein source, it can treat a host of health and mental issues (morning sickness, PMS, nausea, vomiting, migraines, chronic pain, epilepsy, glaucoma, crohn's disease, colitis, diabetes, anxiety, adhd, neuropathy, insomnia, depression, Multiple sclerosis, Alzheimer's, can balance appetite, and is NON-ADDICTIVE, shows promise of being able to cure certain cancers and in combination with western medicine improves effectiveness of Hep C treatment), lubricants for machinery, heating fuel, fertilizer, cattle feed. Also, overdosing is nearly impossible - you would have to ingest many pounds of it to O.D., far more than anyone can fit into their stomach, or if you want to smoke it, you'd die of asphyxiation long before you O.D.
It is also not a gateway drug: there is a greater correlation between either nicotine or alcohol use and hard drugs than there is with cannabis.
Disclaimer: I have never so much as tried pot - I cannot even though it's legal in my state because of my career. I'd like try it myself to treat migraines, but I can't. :-(
Also, if it were legal in my mom's state I'd love to buy some make a tincture for my her to help her with her pain so she can cut down her oxy use (she is on opiates because she is in severe chronic pain and is terminal).