shortcut to turning this function on....

1) Right click on winamp window.
Windows --> Visualisation.
2) On Visualisation panel that opens, click on "Open Editor" button at bottom left.
3) From dropdown menus: Settings --> Display
Turn on following options:
- Overlay mode
- Set desktop to colour
- No minimise on Winamp minimise
4) From dropdown menu again: Settings --> Fullscreen
Select a resolution and colour depth that doesn't grind your machine to a halt !!!!

Play a tune, minimise Winamp and Enjoy....