Take a look at the Google Video Blog (http://googlevideo.blogspot.com/) In the right column, under funny videos, try out that video search that was made with the Google Search Ajax API (http://googleajaxsearchapi.blogspot.com/2006/08/add-video-search-playback-and-tagging.html). It includes tags and playback embedded within the site.

I like it!

I like it too! You can also add & edit tags directly from the AJAX stuff.

Just one thing missing for webmasters : a way to place Adsense ads inside ;-)

It loads way too slow, the video is too small (can be changed). That would be useful for user-defined playlists, not for searches.

The initial load is bit slow, but afterwards, it works pretty fast. For its purpose, the video size seems fine to me.

And, the webmaster can set what categories to search through, so why could it not be used for search.

>>And, the webmaster can set what categories to search through, so why could it not be used for search.

Because you can't control the results. If I'd use that with "google" as a query I'd get a lot of irrelevant results.
http://video.google.com/videosearch?q=google

Oh I see, so that's more a matter of google improving it's search service, so that it can be useful.