The Linux and Open Source Marketing Board

I'm doing some data crunching, but I need averages. My resources for discovering estimated market share of Linux, Windows, Internet Explorer and Firefox are limited. I need these four figures to work out a viable strategy and marketing plan.

If you can, please post any numbers you find to this thread, along with the resource. I'll post more as I find them.

Source: W3Counter (March 2009)
IE (combined): 57.04%
Firefox (combined): 31.07%
Windows (2000, XP, Vista): 87.19%
Linux: 2.10%

Source: Marketshare.hitlinks.com (March 2009)
IE: 66.82%
Firefox: 22.05%
Windows: 88.14%
Linux: 0.9%