This script runs on YouTube API and fetches millions of videos from the API. The script also has a search cloud function, which shows the recent searches people have done worldwide! Another function the script has is that it adds the tags to the DB and counts the number of times its been searched, then it creates a massive tag cloud for the search engines to index.
The script is completly SEO'd for easy search engine indexing, the script has a dynamic Google Sitemap that you can submit to the Google's Webmaster central.
Basically, the script asks you to put in some KeyWords related to the site you want to start up, and then automatically fetches videos from YouTube with those keywords, and then shows them up on your site.
Demo: http://www.whatpcs.com
Script by itself is for 30$
Ask me for Resell Rights if youre interested