Yes, essentially death is the actual veil itself, which is why many shamans feel that they must endure a "death" before being able to become a true shaman. The only way to walk inbetween the worlds is to craft a way to cross the veil and come back. This theory has always fascinated me. The only thing that makes me weary is more than half don't actually come back! It was seen as the ultimate test of the strength of your spirit and if you did come back, you were worthy of the title and blessed. Some took an easier route and would lie in a grave for 3 days straight in trance with someone standing guard to make sure animals did not bother or attack them.
As for this topic, I believe "technology" is the wrong word to use. Spirits are merely on a higher frequency of energy than we are. If you are interested in such things, you should look into parapsychology.