What are Buddhist perspectives on psychedelic drugs? I have head psychedelic drugs described as a gateway that can lead people to Buddhism, and to very powerful meditation practice. I have also heard the drugs were frowned upon by ancient Buddhist teachings. What do you know about the ancient and modern Buddhist attitudes toward these drugs?
John Hopkins is currently doing a boatload of research in this area (e.g.).  While I personally find all this very interesting and cannot possibly argue against the use of psychedelics in palliative care, I don't think they are appropriate in the context of Buddhist practice.  This is especially true for beginners; maybe not so much for advanced practitioners.  The experience of jhana or any mystical experience isn't nearly as important as the journey that gets you there.  As profound as the insights that issue from a bright, malleable mind can be, they are absolutely secondary to the transformation that is won through the sweat, effort, failure, patience, and resolve that characterizes long term meditation practice.  The bumps and bruises are what transform us.  They also better prepare us to receive and make use what wisdom is to be had in the jhana state.