There is an entry for a key generator program in the code archives somewhere.
If you do implement a system such as this, keep in mind that it will never be fool proof. The only way to make sure people can't crack your demo version and unlock the full one, is to not have the 'extra' content included in your demo version in the first place. The convenience of being able to unlock the extra content will be offset by the possibility that people can crack it.
If you do implement a system such as this, keep in mind that it will never be fool proof. The only way to make sure people can't crack your demo version and unlock the full one, is to not have the 'extra' content included in your demo version in the first place. The convenience of being able to unlock the extra content will be offset by the possibility that people can crack it.