If you only need to call your function when creating a site, you could use the Site Created Event Handler. The handler isn't documented yet but it works the same way as the "User Registered" handler, which is documented here.

HTH,
Joe D.

The beauty is that you don't have to call the Event Handler yourself. The way it works is that once your handler is registered in the site, when the target event occurs, your function will be automatically run by the system. To see a sample Site Created event handler, take a look at:

mojoPortal.Business.WebHelpers\SiteCreatedHandlers\DoNothingSiteCreatedEventHandler.cs

Also study the document Joe D. linked, for more background and how to register your new custom handler in your site.

Jamie