I could see it being very useful. I would think a chick was a little strange if she decided to use it all the time, but whatever floats her boat.
I want one for in the car.
Imagine, if you will, driving to florida from ohio (38+hours round trip) with only you and four little girls. The 5 year old decides she HAS to pee. Stop at an exit and there ARE NO BATHROOMS. She won't pee in the bushes because its hard enough for a grown woman, let alone someone who just was potty trained a few years ago. I would have loved one of these.
(I ended up making a "we stop every four hours only" rule. Put pull ups on the 5 and 3 year old. I'm an evil woman)