Pottermore, J.K. Rowlings online Harry Potter universe, has opened up to everyone. The registration process requires a little bit of patience. They will assign you a username (to protect identities and ensure child safety). You will also have to confirm your registration by validating your email, but it is worth it once you are finished.
After you've signed up, you'll get sorted into one of the four Hogwarts houses and you will have a wand choose you. J.K. Rowling and Sony have created an amazing online world to explore.