How to get winamp milkdrop visuals from an external audio source 

Using Winamps Milkdrop visualizer is a great way to add to the atmosphere and runs itself very nicely once set up. So long as your Windows PC (or laptop) has a Line Input, it's easy to get winamp to use any audio you are playing to get great, in time, visualizations... It's just like you had hired a VJ to play along side you.
1. Click "add URL" in the playlist menu.
2. In the URL textbox, type "linein://" but without the quotation marks.
3. Click OK and your PCs line input will be added to the playlist.
Presto