Cosmic by Frank Cottrell Boyce

Liam has always been tall for his age, but now that he is twelve and shaving twice a day, he doesn't really look like the other kids.  His parents want him to fit in with the other kids, but Liam just wants to get out of his home town and see the world. 

One day Liam decided to take advantage of his height.  Everyone always thinks he's an adult, so why shouldn't he get the benefits of being an adult?  He teams up with a classmate named Florida, and they pretend to be father and daughter. 

Everything is great until Liam gets the opportunity to take his daughter on an adventure.  The adventure is more than either one of them bargained for.  Can Liam keep up the pretense that he is Florida's father?  Should he?  As Liam strives to be more "dadly," he and Florida get to know each other better, and they learn to appreciate each other and the importance of a good dad when you're in a tough situation.

I loved this book!  It was funny and touching.  Think Charlie and the Chocolate Factory, but the chocolate factory is a trip to outer space.