It doesn't cure MS, cancer and the rest, just relieves the pain, from my past experience (my younger days) it was cool, but with age and growing wiser, it still is harmful.
Now in pill form, THC, I would believe it is safe, not going through your respiratory system, the lungs, so I wouldn't argue the use for medicinal purposes, it can be a great thing
For recreational purposes, I am not for that anymore, and it can kill like a drunken driver can, both things can cause poor judgment, causing accidents and both have been the cause of many fatal accidents, there were several every month and year where I use to live, one sad thing was a group of teens (3 got killed) and the other paralyzed due to being stoned, there are so many cases like this or where innocent people get killed by some one driving either drunk or stoned.
Best advice to those who believe getting stoned is fun, or drinking, don't drive during that time, for your saftey and others.
Regardless, anything we smoke and inhale can cause lung cancer and esophagal (sp?) cancers as well, it is your friends and your own personal preference / decision.
I am didn't reply to start any debates of the pros and cons of pot, so I hope I haven't trigggered any ill feelings towards me.
Good luck and take care,
DE

In giving advice seek to help, not please your friend
SOLON