If you haven't already heard about it, there's a very cool Winamp plug-in created by Sanchit Bhatnagar, called MiniTube. It let's you find and play music video's based off of music you're playing in Winamp. You can either use the audio from the video clip, or you can "lip-sync" the song's audio file from your library.

Download the Minitube Plug-in from Winamp.com.

Plug-in Description...

Find and play the music video for your mp3 file. So your audio playlist becomes a video playlist! MiniTube will find and stream the music video of your "now playing" mp3 track inside winamp by looking it up on YouTube, Google Video, etc. Think of MiniTube as your own personal VH1, where the music videos are being played from your own Winamp's mp3 playlist. There is an option to lip-sync the videos and your mp3 files in the menu at the bottom (also many options are at bottom). It's the first release so tips for improvement are welcome.