YouTube’s API - basically a read-only set of RSS-feeds and XML/RPC-calls - currently doesn’t support scripted upload or download of videofiles. My quick hack PHPTube offers this featureset in a cleanly encapsulated PHP-class. Special interest goes to the upload-functionality, which virtually allows the integration of YouTube as a video-storage-backend into any other web-app. And while there are several download-scripts out there on the web, I’ve yet to find another uploader.
