Just out of curiosity did you have all of the broken ones at the same time? How did you use that many? as servers? rendering farm?
most of them I had at the same time. I bought them on ebay with missing parts. Every one of them not have a power supply. So I was going to repair one at a time.
Some of the computers I ended up damaging in the repair attempts.
Blue and White G3: My very first two

Mac. I bought these two at same time in ebay auction. For like $0.99 each not including shipping. Nothing else included, which I bought later. Right now I only have one monitor (which is one reason why I prefer

iMac, and all laptops and netbooks everywhere) a ViewSonic VX2245WM and the Blue & White had 9.2.2 in it, and it adjusted to the monitor resolution!!

Unfortunately this was before Classilla, and so I went through numerous upgrade process to be able to boot Tiger on it. I got a larger hard drive, extra hard drive card, etc. (and also added USBs... also I love the Blue & White because they contain ADB Keyboard Port) These processors are way too small for Tiger, plus I bet some of the hardware was defective. I went back to 9.2.2 once Classilla was released.

The extra Blue & White I was going to repair, but, I ended up using it for parts, and then one of them sparked.
PowerBook 1400 series: again I was a complete idiot. The keyboard malfunctioned on one of them, and I tried to temporarily replace keyboard with other one, as it did not have built in ethernet. I stripped a screw, forced heatsink off, ... and then after the damage was done I realized that these powerbooks have external ADB keyboard slot, which I in fact have a working ADB keyboard!!
So I only had a few of these working at a time.
Soon I will get all the tools need for ANY and EVERY repair.
I must update my inventory of
I now have 3 broken powerbooks. I don't have any of them.
I now have added to collection:
3

clamshell ibooks. 9.2.2 and OS X Cheetah Edition. But I only use them to boot into 9.2.2. All they need is RAM upgrade. They even came with Power Supplies.... Yo-Yo ones!!

All have AirPort card. Batteries on all of them, and two of the batteries work.
I use them for everything except of what you mentioned lol. I have them all as spares right now...in case one breaks I can repair them conveniently and not stress about them. Also, I keep one computer on at all times... so what I do is put one to sleep after 24 hours of uptime, and then I wake another one up. This way they should not wear out.
I do not know how to turn them into servers.
I also have never heard of the term rendering farm before.

But they do sound like nice ideas!!
