Where is the best place to store cord blood after a pregnancy?

In the baby! For most of human history and in all other mammals, the cord isn't cut until it has stopped pulsing - giving the baby iron that lasts for months and stem cells that could last a lifetime. One of my goals is to make optimal cord clamping the norm today, rather than the rush to clamp so common.
A specialized bank. The cord blood banks aren't as tightly regulated as blood banks, yet, but it's the only acceptable way to store stem cells as of now.