For those who for various reasons do not want to think "out of the box" or who sees Windows as "inevitable" or "it comes with the PC so it is free" the following could be interesting reading:
Wal-Mart in USA sells out 10 000 Linux $200 PCs in 2 weeks
Dell is now selling PCs with Ubuntu Linux preinstalled and Lenovo (old IBM) has announced they are going to sell PCs with Suse Linux.
For those who might want to see how the gOS (Google OS more or less) in the Wal-Mart PC looks here is a link.
I think it is slowly gaining momentum. Several reasons, one being that Windows Vista is a nice-looking but beastly system, another is cost-related and I think also that many are getting sick of having to fight virus and spyware and younameit with extra software on a daily basis. Not to mention hardly being allowed to reinstall your computer should you need.
Finally if you think today's computers are boring have a look at this! One just have to love the person's dedication if nothing else...