As an individual, is it possible to have two different credit scores if rated by two different agencies, just as a corporation can have different credit ratings based on the rating agency?
Yes it is very likely that you will have different credit scores for the different companies. keep in mind the different companies have different algorithms. Also some creditors may not report information to the different companies. It is possible that a mistake doesn't appear in all the companies, thus giving different results.
Also remember that your score can change everyday, because some of the numbers used are a snapshot. Your credit utilization changes with every charge, and every payment; but is only reported to the credit agencies monthly. If you have multiple cards, loans, lines of credit, the utilization rate might change several times a month.
Yes, in fact it is more likely than not that your scores will be somewhat different among different agencies. But they should not be radically different.