If you have acces the the search template of your theme you could place this (monster of a) code there, maybe below the WP search:
<?php
$RYTVAPI = new RelatedYouTubeVideos_API();
$RYTV_config = array(
'orderBy' => 'relevance',
'numberOfResults' => 5,
'width' => 480,
'height' => 360
);
$youTubeResults = $RYTVAPI->searchYouTube( get_search_query(), $RYTV_config['orderBy'], 0, $RYTV_config['numberOfResults'] );
echo $RYTVAPI->displayResults(
$youTubeResults,
array(
'id' => 'relatedVideos',
'width' => $RYTV_config['width'],
'height' => $RYTV_config['height']
)
);
?>
I’m not sure if or how you can hook into the process of showing the normal search results. But if I find a way I will implement the option so you wouldn’t have to fiddle with your theme’s template code.