Floating Flower Tip - Most flowers float pretty well on their own until they start to pool with water and slowly sink. For a longer lasting centerpiece, use bubble wrap to make little skirts for your flowers.
TEACHER GIFT (Or Room mom gift)! A little gift for summertime (towel, suntan lotion and a magazine or two). A student once gave me this in a cooler tote. One of the best gifts I've ever received at the end of the school year!