This is a great tip and I have been doing it for years. Trim the ends off the parsley and cilantro and put in a small vase or big coffee cup filled 3/4 of the way with water. Store in refrigerator. The herbs will last for weeks this way. Seriously. Check the water levels and change out the water at least once a week.
*I rotate two vases I saved from edible arrangements I got as gifts. They are the perfect size and are really pretty!