Yup, that's right Thunder. You're the Universal Donor.
Anyone, can receive your blood.
You are what they call, probably one of the most valuable blood types on the planet.
The downside, you can ONLY receive O Negative blood.
Interestingly enough, rh negative persons can give to rh positive people, but not vice-versa, even within their own alpha type. Thus it is safe for me to give my blood (A Negative) to an (A Positive) person, but not the other way around, as it will cause a very strange and peculiar rh immune response from my body.
But yessiree: O Neg. is the one that is always sought after, because in an emergency, it can be safely transfused.
If you don't know your blood type folks: find out. If you are planning on having a family/children, it's important to know, due to possible rh incompatibility.