Livetube player, originally created for Livetube.fm DJs, allows you to make bulk queries to YouTube and Last.fm, share videos to Facebook/Twitter, access Youtube playlists, and watch videos in fullscreen. If you feel ready, you can also become a DJ yourself with your own live event.
Jaksta is an easy way to download and convert video, audio, and MP3s from the Web to your Mac. Just open Jaksta, then play a video or song in your browser, and Jaksta saves a copy to your Mac's hard disk, or converts it to several popular device formats. It works with thousands of sites, including YouTube and Facebook, as well as popular music sites.