Just for keeping everything the administrating easy on the backend, first make a list of the authorized users en put them in a usergroup in Active Directory.

• Go to the Central Administration and open the Shared Service Provider for your web application.
• Select  “Personalization services permissions”.
• On the next page you’ll see a list where you could allow or deny certain functionality to certain groups. There you could define who’s allowed to create a MySite and who’s not. In this case you put the created AD group to the autohorized groups and give them the personal site authorisation.

Source: Microsoft MOSS2007