There is a program called utlramon for windows that already does this [mentioned above]. A Linux ultramon doesn’t exist, well not as a separate program, as the functionality already exists in gnome.

Just add a panel to each monitor you want, and add to that panel a window list. That’s it.

Instructions:
1.) Right click on anywhere on the launchbar, click “New Panel”

[UPDATE: 2010/05/02 added ALT]
2.) hold down ALT + Drag the new panel to any monitor/location.
3.) Right click on that panel, and click “Add to Panel”
4.) Select “Window List” under Desktop and Windows
5.) Click Add.
6.) Click Close, and you’re done.

Now I don’t have a cluster of ALL windows on my three head setup on one taskbar.

If this helps, please drop a line in the comments.