Recently, we've "rediscovered" my wife's Rh negative blood type. We had known about her blood type due to issues when the kids were born but actually never knew all the theories about the blood. It was just one of those things you never think about or never realized had any real significance except during pregnancy. There are other things happening around us presently related to the Rh- but I'm keeping quiet about that stuff - at least for now.
Recommended books: Bloodline of the Gods: Unravel the Mystery in the Human Blood Type to Reveal the Aliens Among Us by Nick Redfern.
The Levite Priest and The RH Negative Blood Type by Roberta Ruth Hill.
For more information check out Missing 411 and David Paulides