The official video keyword tool from the Tube itself. The YouTube keyword tool can help identify popular topics and queries, but currently does not offer any additional information (average monthly searches, clickthrough rate, etc.). Still useful for beginning your research.

YouTube Groups are a great way to get involved in the YouTube community ! Groups allow you to share ideas, opinions, and (of course) videos with like-minded users. YouTube doesn't offer an easy way to search for groups, but you can use this custom search engine to find relevant groups to join.

TubeMogul is a free service that provides a single point for deploying uploads to the top video sharing sites, and powerful analytics on who, what, and how videos are being viewed.