One of my favorite gifts was flower pots. Just the cheap clay pots from Home Depot or something. We had painted and decorated them. After all the decorations had dried, the pots were filled with dirt, a few pansy seeds were added, and handed to the girls with directions to shower the plant with love and water and told to wait. Depending on the length of the pledge period and how well the girls take care of it, the plant should be blooming around the time the NM is over.
It did lead to a funny rumor, too. It was rumored on campus that if the NM's plant didn't bloom they wouldn't be initiated. Something about not caring enough for a plant so you can't care that much for your sisters.