Many people have gotten better without the use of medicine and many successful people have said that if you put your mind to it, you can do many great things. Why would someone be unwell, if they felt they were alright? People can use their minds to do all sorts of things, why not heal?
For trials, it's a resounding, unqualified yes. Without placebos, how can we know that a medication is truly effective?
For actual treatment, only sometimes. The American culture has a lot of hypochondriacs, with commercials for medicines all over TV and people who panic and suddenly the reason why they fidget at night must be restless leg syndrome! If someone doesn't have a disease that actually needs treatment, handing out a placebo is much easier than trying to convince them that they're fine (ought to be last resort, though, and preferably for habitual complainers).
Also, sometimes adding a placebo to real treatment can help efficacy. The brain is powerful, and if we can make it work for us, why not do so?
I think that as long as they are used effectively and at a time when someone's health would not be put in immediate peril or otherwise compromised in some way, then yes, placebo treatments should indeed be used in medicine. They can actually be quite effective at times for people.
I think in this day and age, too many people are self diagnosing themselves. Even worse, people see all these ads for prescription drugs, and they automatically think that they need them. I think it could be beneficial or have interesting results if placebos are given out. As long as the patient doesn't have a live or death situation and needs real drugs, I think it couldn't hurt.
Placebos are about 22% effective at treating disease X (give or take) with conventional medicine anywhere between 30-90% effective at treating disease X. So off the bat the real medicine is more effective, and ironically people are just as if not more likely to get serious side effects from the placebo then the real medicine when they believe it to be strong medicine (Not aspirin). An additional problem presents itself and its called the Anebo effect. It's the exact opposite of the placebo effect, if a patient believes the treatment is less effective or not real, they are less likely to heal then if they got a placebo and believed it was real (Singulair Clinical Trials) and the difference is significant, about the same as the placebo effect.