Dyson Sphere!!!! That's the kiddy! I knew I was missing something.

http://en.wikipedia.org/wiki/Dyson_sphere

However, that's only about a system of satallites, not a hollow planet.
Ringworld images are a better way to go!

Available on Amazon for the Kindle E-Reader

All the Woes of a World by Jonathan Icknield aka The Bryster

And in my final hours - I would cling rather to the tattooed hand of kindness - than the unblemished hand of hate...