This tiny Mac has a Motorola 68000 processor running at 8 MHz, and (as its name implies) 128 kilobytes of RAM. It has a single, 400K disk drive. Nonetheless, this Mac boots in 1/8th the time of my neighbor's Pentium 100 running Windows 95, and also has a multitasking, 32-bit GUI OS (the Mac OS).
I purchased this Mac for $20 at a trade show. It was very sick-- the screen flickered on and off (loose solder joint), it had no startup disk, and it would crash constantly (maladjusted power supply- it was putting out 4.2 volts instead of 5). After some soldering and scrounging (for a system 2.0 startup disk), it's now a happy Mac.
In order to make it useable, I wrote a small VT100 emulator for it, and set it up in my girlfriend's dorm room as a terminal. If you'd like to download the tiny serial VT100 emulator for any Mac, click here. If you want the source code for a general-purpose VT100 emulator, click here.
After a while of that, my girlfriend decided to just buy a PowerBook 1400.