I'm a shaman. I'm not afraid to say that, for any of the various reasons one could be.
I've tripped only a handful of times and have really learned little after my first experience, but I have learned. The first experience was as much of a opening of new doors as would be getting sucked through a high pressure hole inside out. It was not comforting :).
But what I have learned was incredibly valuable. On my way down to the darkest abyss one can experience, I climbed my way to the top again. Remembering every foot hold and pathway I took. I've been able to go back and forth from complete desolation of the soul and mind, to euphoria, and with such an ability have used to to "save" some people. I've had a handful of people email me, responding to various messages, about the words I've put out, that "saved their life".
Due to the fact that this happens, and probably will continue to happen, I never outright condone the use of psychedelics. I know their intensity, and I know the fragility of some perspectives of reality, and mixing the two can have catastrophic effects. People must show a great deal of understanding, education, and self-improvement, which is incredibly important when dealing with these substances - with an intent of spirituality, or at least something beyond "Getting high" and laughing at colors.
I've been able to help only because I have been there. I know the steps one needs to take, rather than the leaps that one wants to take (or others impose). The road from an intense, bad trip, can be a terrifying experience, with a rewarding ending.
Beyond that, however, I have realized a special ability that comes and goes - the ability to see sickness. While I was on a very low dose of ayahuasca I was able to see what was ailing people. For weeks after wards my ability to give back massages was incredibly rewarding, and actually very psychologically stimulating (as I could literally "See" the pain).
This ability to see sickness, is what I believe a true shaman holds. It is a learned trait, not something born into. It is not genetic (I don't think), so I'd hope others may be able to gain this as well.
Shamans of the brazilian rainforest are known for their ability to "see" parasites and sickness long before the conscious mind sees symptoms. Often times, weeks before one would normally go into the hospital. This is not some magical trait, or some divine information - this is simply an extremely acute sense of non-verbal communication. Our brains are extremely similar across the globe, the make up, the neurology, even the psychology - we all have very relate able (conserved) portions of the brain. A shaman knows these like the back of his or her hand, and can see when these portions are acting odd.
The stomach may seem loose, the eyes may be slightly drooped. The shoulders sunken, and heavy. The steps may be rigid, or unbalanced. Our minds adapt quickly to pain & suffering, so many times we may not even know we are in pain at all! Yet to the trained eye, all ailments become highlighted like neon-signs. Curing, is something I do not understand, and have much to learn about. Much has to do with placebo (sorry, I'd like another word) and much has to do with things beyond my understanding. Often the shaman will go into the forest, and plants will "speak" to him or her, presenting themselves for the healing process. Here the shaman takes plants which he knows to be familiar, but really has no understanding of medicinal action, and cures.
I hope to one day obtain this kind of hospitality, this ability to heal, cure, and help beyond some internet-arm-chair-psychology.