Hull Sphere

Hi there, I was wondering how to make a perfect circle with the block, and when I founded the solution with this image:

 again I wondered, and a sphere?!!

So I spent last 2 hour making this sphere,

Details: 

- Number of blocks: 21.376

- Dimensions: 62x62x62

You can see all pics in the imgur album at: http://imgur.com/a/pkBh5

Download link: http://star-made.org/node/7724