WatchVideo Can Download, Rip, Convert And Play Videos From YouTube And Many Other Video Sharing Websites

WatchVideo is a Qt application (but also comes with a command-line version) to play, download, rip or convert (to Ogg) videos from Bliptv, Break, CaracolTV, CineGratis24h, CollegeHumor, Current, Dailymotion, Metacafe, Sapovideos, TheOnion, Vimeo, YouTube, and others. 

What makes WatchVideo special is that besides being able to download videos from many video sharing websites, it can also rip/convert and play them, either using an external player (such as Totem or VLC) or you can use the internal player (mplayer - this is an experimental feature in the latest version). The rip/convert/play actions can be set to occur once a video has finished downloading which is a real time-saver feature. WatchVideo also comes with NotifyOSD notifications for Ubuntu users.

Another interesting option is called "Search Browser" - this can search your browser tabs for open YouTube videos and import them into WatchVideo. Unfortunately, this feature currently only works with Firefox 3.6 (I've tested it with 4.0 beta and it doesn't work).

There's only one thing missing in WatchVideo: a feature to be able to search for YouTube (and possibly other websites too) videos from the application so you won't need a browser for this.

Install WatchVideo in Ubuntu

I've debianized WatchVideo it and uploaded it to the WebUpd8 PPA so you can easily install it in Ubuntu 10.04 and 10.10. To add the WebUpd8 PPA and install WatchVideo, use the following commands:

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install watchvideo

Once installed, you can launch it via Applications > Sound & Video > WatchVideo. For the command line version, run:

watchvideo_cli --help

The latest WatchVideo (which is available in the WebUpd8 PPA) is currently in beta so in case you encounter a bug, you can tell the developer about it at WatchVideo QT-Apps page.

Note: I've only tested WatchVideo in Ubuntu 32bit so I'm not sure if it works on 64bit (it's Python so it should work, but I'm not 100% about the dependencies). Pareja confirmed in a comment below that it works on 64bit too.