Windows only: Winamp plug-in MiniTube adds YouTube videos to your music playlist. Fire up MiniTube when you want to see your music as well as hear it, and it searches YouTube for a video that matches the metadata on your MP3 file, and starts playing it along with the music automatically. In theory this is awesome, but MiniTube's implementation falls short in one main way: the video often starts after the song does, so it's not necessarily synced with what you're hearing. If you can't stand being a few beats behind, however, you can opt to listen to the YouTube audio instead of your MP3 file. MiniTube is a free download that works with Winamp.