Yes, I have first hand experience with altered states of consciousness due to meditation. I'll give you an example of something that happened to me recently as the result of meditation.

I was feeling content and peaceful at this point. After the shower I was drying myself off when all of a sudden the bathroom got brighter. It was as if I â??woke upâ?, more like I was â??shockedâ? awake. It just sort of happened. I felt no desire for anything. My mind was split in two. â??Iâ? was witnessing my ego trying to make sense of what was happening. It was a loss of self. Pure bliss flooded my body. I was very joyful. Immediately I thought of the Buddha and of what happened to him when he reached Enlightenment. The demon of ego and desire sent his beautiful daughters to tempt the Buddha (in his mind), but he merely gazed upon them, feeling no desire for them, merely witnessing their presence. Thatâ??s how I felt that night. I was merely the witness. I felt no desire for sleep, for food, sex, anything like that. I was content with just being. Walking into my room, with a Buddha smile on my face, I remember this incredible energy radiating off of me and when I walked into my empty room, I felt this strong presence as I entered. I felt like the whole universe could feel me and I could feel the whole universe.

This really did happen to me. It was a glimpse into enlightenment I've found out. I just wish I could reach it again, but permenetly this time. I know one day I will since this happened to me after only a few months of practicing yoga and meditation. Ever since then I've been on a different plane of existence it seems, a higher state of consciousness. My thinking is better, I can visualize things to the point that I think I'm seeing it actually, I'm just overall a better person because of that experience. More things then that happened to me that night, that was just the most amazing thing.