New
#11
You could get an Objectbar such as this:
Mr-Ragnarok's deviantART Gallery
It will replace the taskbar and offer a lot more functionality akin to the Mac bar. It will perform the way you are wanting if you don't mind the different style. Bars like this are highly customizable as well. They just have a small learning curve to adjust to.
Edit: I serendipitously came across this today. It does what you are wanting, hides the opened program/folder from showing on the taskbar.
http://www.box.net/shared/u1suyf1l8erhnex3mps4
Hope that helps.
Last edited by donnellyd; 19 Aug 2011 at 13:36.