What are the different ways in which stem cells can be harvested/produced?

As far as I know there are a few way's to get stem cells, but not all of these harvest the same kind of stem cells.
1. Embryonic stem cells; they are harvested out of embryo's. These stem cells can differentiate into any other cell and are therefore very useful. New techniques are being developed to harvest these stem cells without causing any harm on the embryo.
2. Adult stem cells; they can be found in both children and adults. They can differentiate, but not as much as embryonic stem cells, and are therefore less useful. They can be harvested out of umbilical cord blood, bone marrow and some scientists say even out of foreskin.
Stem cells can be used to cure cancer, Parkinson's disease, spinal cord injuries, Amyotrophic lateral sclerosis, multiple sclerosis and muscle damage, but further research needs to be done.
This is just in a nutshell, but I hope this helps! If anda want to know more; there is a lot of information on the Internet, but a lot of it is explained quite complicated. It is interesting though!