The image that ALWAYS comes into my mind when I hear mysticism is some guy in the lotus position, but it means a lot more than that to me. Mysticism seems to refer to the ability to interact with whatever exists outside the physical, material world. It's about transcension, about going beyond what most people can imagine, to get to the deep truths of the universe.
However, I also view mysticism as something secular, something that precludes God as we think of him. When I think of mysticism, I think of some sort of underlying "energy" in the universe...as if we searched for God, and we found the truth: that what we call God is just another natural law permeating our existence.
Because of that, I think it would be interesting to get into it and see where it takes me, but I don't want to because of my faith in the Biblical God.