Hi! I think that you should def. get both the students and your cooperating teacher a gift. For the students, I remeber I made little gift bags for each student and put in things like pencils, erasers, and a couple other fun, yet useful, items. Try a company like oriental trading to buy in bulk (its a lot cheaper!). Also, I brought in cupcakes for the students as well. As far as your co-op, something personal like the person above me said. A gift card is good. I remember I got mine a gift card and a book that she mentioned she was going to buy herself. Whatever you buy the students and your co-op i'm sure they will all love! Good luck and enjoy your final days!