Cool. Where did you order your parts from? I've been tossing around the idea of buying a new machine but I have yet to justify the reasons why - maybe I'll just fry my old one.

Let me get this straight, you fried one machine by overclocking it, and used it as an excuse to buy another machine which you again overclocked? And your wife let you back into your house?

Has AMD improved their handling of overtemperature conditions? Having fried a 1ghz AMD when the fan driving it
failed, I am biased against them. P4s will throttle down to keep their temperature within reasonable norms, which seems like a better solution.

But what do I know, I still have my old Abit BP6 with dual 400 Celerons (running at 400Mhz, I'm a wimp.)

I was a bit amazed at my wife's acceptance as well.
When I played with the settings on my old machine, I really didn't know what I was doing. That alone guaranteed that I would screw my old computer up somehow. I spent a lot of time reading up on overclocking before I bought my new stuff and before I played with the new machine. Sites that are priceless are:
Tweaktown
ExtremeOverclocking
OC Workbench
Overclockersclub
Blarg OC
There is also a guide that was indispensable for my initial overclocking, but I don’t have the url here at work. I’ll add it when I get home.
The setting change I made in the old machine was the equivalent of changing the gas in a Geo Metro to ethanol. It promptly blew the engine. My old MB was a ASUS KT133, and you’re right, it had no security for over temp conditions. Additionally, if you set the processor to out of range limits, it would fail to POST. The only way to remedy this was to erase the CMOS and start over. My new ASUS MB now includes temperature shut down parameters. More importantly, the AMD XP line of chips themselves now shutdown at the edge of the temperature envelope rather than cooking. This did not exist for previous revisions.
Perhaps the most useful change in new Asus motherboards is the CMOS is now aware of overclocking conditions. When I got my new machine, I could move settings up, and when I exceeded the acceptable limits of one component and the machine would not POST, the bios would boot into safe mode and immediately place me in the bios with a stern warning "the settings you have chosen exceeds the blah, blah etc." Because of this, I could basically do any thing I wanted to the settings, and if the machine failed to POST, a quick power off would bring me back to the bios - with all my settings intact, just not engaged. It is sort of overclocking for dummies.
As for the actual overclocking, you know that you can only push the CPU only so far before it is out of spec. Upping the FSB will lead to this happening quickly with low CPU settings, so unlocking CPU is required. Previously this required actually modifying the CPU itself, using conductive material. The A7V8X allows you to unlock and change the multiplier of the CPU right in the Bios, no chip altering required. This allowed me to twiddle to my hearts delight without any danger at all. I could up the FSB, and lower the CPU multiplier and go back and forth to find the best settings.
As for heat, it is a very big issue. I bought the very best air-cooled heatsink on the market, the Thermalright SLK-800. However, as you raise the overclocking freq on you machine, you are eating into the overhead the chip was designed with. To make the machine stable, you usually need to step up the core voltages for the memory, CPU and AGP bus. This causes the temps to climb even further. You have a 4 way balancing act between FPS/CPU/Voltage and heat. I'm actually considering going to a water block to lower my temps. (47C idle and 52C load). The newer motherboard and XP CPUs are now temp failsafe, but I would never trust it.
In the long run, it still looks like P4s are faster. They have a faster memory bandwidth (hugely faster), but the chips are by default locked, and I don’t know if you can unlock them. This results in very limited overclocking capability. The heat issue has been addressed by AMD, and Athlons are certainly cheaper.
I got most of my gear from newegg.com and mwave.com. At the time I thought I was buying the fastest AMD motherboard and best components, but the reviews on overclocking sites revealed that there may be one or two components that would have been better choices, especially in the motherboard department. All in all it’s a very inexpensive way to get a very fast machine. Checkout the product reviews from the overclocking sites, they will have comparisons and recommendations on all types of hardware, including what I got.

Kevin, I'm a real novice with PC's but wondered if I should change the CMOS (bit you get into at startup pressing DEL?) settings for CPU Warning Temp from 'Disabled' to the highest temp, also with system temp setting. I've got an Athlon XP2200+ on an MSI board that has a DDR333 chipset, and after running IL2 flight sim for a bit (Ti4600 graphics card) the system temp was 50'C, CPU temp 63'C (39 & 53 on first start up). I think the fan is 'AKASA'. Worried about burning it out after reading your interesting PC build article! Cheers

Ehi, Scotts, my new XP 2000+ has the same temp of yours; the heatsink was an aluminium one, but it is required a copper heatsink for such a cpu (due to the little surface of thoro core). I'm managing to change it: it will lower the temp, sure. Another thing: if you have an ASUS A7V8x mb, you could download the last version of the BIOS (1010), fixing all thermal problems (you should gain about 10° C, they say).
I suggest you to buy a copper heatsink (yours is surely an alu one) and to use Vcool, a great cooling software: in some minutes of idle cpu my temp lower from 62-63° C to 46-48° C (I have a mb temp of 30-32°C: yours is quite high!).