UberTuber grabs clips from various sites and opens them in your media player while they're being downloaded. The Python script youtube-dl downloads the video file to the temporary folder. From there it is either played back while it gets downloaded or moved to another location determined in a file dialog.
UberTuber monitors the system clipboard for URLs pointing to the supported websites and automatically inserts them into its URL text field.
If the playback of a clip from a particular website works, depends on the underlying youtube-dl script, which gets updated from time to time. At this moment there is support for clips from:
YouTube, Google video, MetaCafe, DailyMotion, Yahoo video, Photobucket, DepositFiles, Vimeo.com, blip.tv, Facebook video, Escapist magazine and many more
For a complete list, check http://rg3.github.io/youtube-dl/supportedsites.html