Any ideas for creating blocks inside of a block?

I am working on a simple module that builds a block containing a tabbed box with 4 areas in it. I thought I could then add new block regions to each of those areas. WRONG!

So, my question is how can you build a block and inside that block call other blocks? The idea is I can have a chunk of blocks with additional info that can be turned on and off using the blocks maintenance user interface.

I have been themeing Drupal for a while and I am comfortable with developing modules. My tabbedlink.module code is pasted below:

// Other module code above including hook_block removed for post

case 'view':
		
		$tab_label = variable_get('tabbed_feeds_label','tab name');
		$tabbed_link_content = '<div id="'.$tab_label.'">';
		if ($tab1){
  				$tabbed_link_content .= '<div id="tab1" class="region">'.$tab1.'</div>';
  		}
		$tabbed_link_content .= '</div>';
		$block['content'] = $tabbed_link_content;
		return $block;

My theme.info file includes:


regions[tab1]= Tab 1


I can add the 'if' statement to my page.tpl.php and the block region returns the content fine.

Any thoughts on this?