Line a colander with four-layered cheese cloth and place the colander on top of a pan.
In a bowl mix the sour cream with yogurt and pour the mixture over the cheese cloth.
Cover the mixture with the ends of the cloth, transfer to the fridge and let sit for 4 hours. When the mixture begins to get firmer, place a plate on top and load it with something heavy (another bowl filled with water, for example).
Let the whey drain from the future cheese up to 14 hours. The time depends on how firm you want your cheese to be.
When the time is up, unwrap the cheese and enjoy!
Your cream cheese will last as long as your yogurt and sour cream would, so check the expiration date.