I'm looking to put together a video of UFO related material, possibly for upload to Youtube etc. Where can I download free copies of material?

I would highly doubt that there is any UFO footage available that isn't copywrit.

Plenty to download from Youtube

Since it's almost all on Youtube etc I can't see what you will find that's either not on there or won't be within days.

Personally, I wish the stuff wasn't on those sites because of the compression used to store it...But something is better than nothing..