Want to totally freak yourself out? The Boston Globe is here to help, with tips on how to make yourself hallucinate LSD-free.

The first thing to know is that the mind isn't a mirror, or even a passive observer of reality. Much of what we think of as being out there actually comes from in here, and is a byproduct of how the brain processes sensation. In recent years scientists have come up with a number of simple tricks that expose the artifice of our senses, so that we end up perceiving what we know isn't real - tweaking the cortex to produce something uncannily like hallucinations.

Intriguing, yes? Here's one of the tricks: Tune a radio station to pure static (preferably not between the hours of two and four, thanks!). Next, lie down and tape half a ping-pong ball over each eye. What you're going for here is sensory deprivation, so I assume some other sort of blindfold could work, but the Globe says ping-pong balls, and I report faithfully. They say that within minutes, "you should begin to experience a bizarre set of sensory distortions," things like seeing "horses prancing in the clouds" and hearing the voice of a dead relative. It's called the Ganzfield Procedure. Trippy!