Where to get a Windows 8 Product Key

Now that Windows 8 has been commercially released Microsoft is no longer providing free product keys for testing.  You now have three options to install Windows 8:

1. Purchase a retail copy of Windows 8 for as little as $14.99.
2. Install the Windows 8 Enterprise Evaluation edition.
3. Create a custom boot ISO that can install Windows 8 without a product key.