I'm going to tell you right now that 90% of you have never seen a Blue Screen of Death, not really. When Microsoft released Windows NT in 1993 when it would crash it would show a blue screen with a listing of all of the contents of the variables in memory when it happened. It also placed these in a file. This was a "dump" of the memory and it helped developers find out what happened when the program crashed.
I get something similar when I have a program crash on the mainframe or when I place debugging statements in my code. Lemmie tell you - reading these things is fun.
I was reminded of this ability of NT (which carries over into Windows 2000 and XP) when I resized TightVNC the other day on my work machine (which runs 2000). It went to the Blue Screen of Death. The thing is, when NT/2K/XP goes to a BSOD, it really is death - there's no recovery to be had, the system just stops.
Windows 95, 98 and ME are not actually the 32-bit cousins of the NT bloodline they claim to be - they're really more like a 32-bit MS-DOS with a Windows program on top of it. Certian things in the 9x line can cause a bad crash to happen and the screen will turn blue with information on it. The difference, besides being a completely different type of screen, is that it's still possible to continue in 9x sometimes, if only to shut the system down quickly. Even when an exception has occured and hitting "enter" on that blue screen just leads to another, it's still better than the no option at all on the NT line.
Most people never even see the real BSOD in XP since by default XP will reboot - you have to enable this and then you'll see the real BSOD when it happens. Once people started seeing the blue screen in 9x enough times and heard about the BSOD in NT, that term started becoming attached to the 9x variant on the screen. However, since most people never work with a NT operating system, most people have never seen a real BSOD.
I use the term BSOD when I see a 9x OS have it, so I'm not saying I'm some sort of prude and most people are idiots. However, since Apple has seen fit to incorporate BSOD into a commercial I thought I'd clear all this up.