I bought a refurbished Thinkpad T40 in March with a 90-day manufacturer's warranty. After having it for about two months, the USB ports died and the video card started flaking out everytime I pressed the machine in the wrong spot. This was about the time when finals were approching fast and I could not live without my laptop, so I sucked it up and decided I would just pay to get it fixed out of warranty after the end of the semester. This afternoon I found the invoice and called IBM. It turns out that in IBM-land a 90-day warranty that started in March expires in October so they are going fix it for free.
Additionally, in the past I have told Dell customer support representatives that the machine I'm calling about does not have Windows installed. Their response has pretty much universally been, "Then it's your problem, not ours." I told the IBM tech support guy the same thing and he said, "We don't care about that."
Hurray for IBM!