If you can use WebGL effects for what you're doing, you could try this
(I was using this effect for a game in which a planet explodes! :P)
The basic idea of it is a TiledBackground object with a seamless Earth Texture and the Sphere Effect on it. The rotating is just the Tiled Background object moving right to left.
I would imagine adding touch responses to it would be fairly simple.
As for selecting continents, you'll have to figure that out! :P