I bought the $3 cups at Wal-mart- they have different colors during the different seasons. I bought the orange, red, green and blue ones. They look very similair to the Dollar Tree ones but they have a rubber gripper thing around the middle of them and the cups are clear with colored straws and grippers. I bought vinyl decals off a seller on Etsy to have the first letter of everyone's name so everyone can tell their cups apart! Allie- Are you putting a note in the cups so people know to use the cups on the trip? I think we are going to have a pre-Mexico gathering at our house before we leave to hand out all the bags before we leave for Mexico that leave around us, so we only have to bring about 4 bags with us for the out of town people. I am planning on putting the cups, Tums, hand sanitizer, welcome letter and timeline in mine. I might buy cheap sunglasses and small things of sunscreen if we can find it also.