After reading this thread, I decided to decorate my band as well as my sister's band for our trip next week!
I'm not as creative as some of you, but I am very happy with how these turned out! (I am still waiting for them to dry completely, but the nail polish doesn't seem to be cracking at all when I put the band on my wrist.)
http://imageshack.us/photo/my-images/10/dgtk.jpg/ Mine is the one on the left. I used clear glittery nail polish on my blue band, and purple glittery polish for the Mickey. I used a teal glittery polish on my sister's blue band, and pink glittery polish on her Mickey. I also traced around the Mickeys with a fine-tipped black Sharpie. I did two layers of each color, and put clear top coat over everything.