Here's a cool new keyword tool that uses Youtube search queries...Youtube is now actually the #2 most searched site, after Google.Note the 3 different modes:
1 Descriptive words or phrases (e.g. green tea)
2 YouTube video id or url (e.g. youtube.com/watch?v=JgT4aS5_Zrw)
3 Demographic BETA
https://ads.youtube.com/keyword_tool