If you've just bought my new book and were looking for the completed exercises, I've posted them at the link below:

http://www.marcmercuri.com/downloads/beginningcardspacecode.zip

As some of the code focuses on and/or builds upon code that exists in existing projects (that evolve outside the book), refer to the links in those chapters for links to where the base projects can be found. 

This download should be available on the APress website next week as well.