Set the GP footer widgets with a function

gistfile1.php

add_filter('generate_footer_widgets','generate_custom_footer_widgets');
function generate_custom_footer_widgets()
{
	// If we're on the posts page, set a number of footer widgets
	if ( is_home() ) :
		return '3'; // Show 3 footer widgets
	endif;
	
	// If we're on a category, show a different number of widgets
	if ( is_category() ) :
		return '5'; // Show 5 footer widgets
	endif;
	
	// For everything else, return the default
	return $widgets;
}