How to update 'Site Title' from custom settings API

Hi folks.

I am a little stuck on something at the mo. I am using the WP Settings API to create some custom admin options pages. One of them saves business info such as business name, address, telephone etc.

I would actually like business name to hook up to ‘Site Title’ so that this can be set when a user first creates a site.

Do you know if this option can be updated in the DB via a field in the Settings API and if so could you provide any guidelines?

My current code for the business name in the settings page is:

$this->settings['business_name'] = array(
'title' => __( 'Business Name' ),
'desc' => __( 'Your full business name as you would like it to be displayed.' ),
'id' => 'busname',
'std' => $blog_title,
'type' => 'text',
'section' => 'general'
);

I have searched the net and have not found much that is any good.

Many thanks for any help!