OK. It's consistently working.
Excellent. I'm glad you have it working.
The first two ATTiny's that I worked with are write offs, as far as I know. If I can ever get my AVR Dragon figured out, I'll try some HVSP.
Bummer.
There are two other things you can try: 1. smeezekitty has published a version of the ArduinoISP sketch that uses a very slow SPI clock. If you accidentally set the fuses to a slow processor clock speed you may be able to recover using his sketch.
2. If you accidentally set the fuses to use an external crystal or resonator you can provide a clock signal on the XTAL1 pin to recover. I believe LadyAda has published a version of the ArduinoISP sketch that provides a 1 MHz clock output suitable for such recovery.
But, your time is probably better spent getting HVSP working.
I'm consistently able to get the first five pins (0-4) working as outputs.
Excellent.
I can't get the last one (the one that is the ATTiny reset pin) to work as a real output.
The RESET pin will only function as an I/O pin after disabling reset (a fuse setting). Once you disable reset you will only be able to reprogram the processor using HVSP. Tread cautiously or you will brick another processor.
If I connect it, it is incredibly dim.
That would be the internal pullup resistor providing a very tiny amount of current to your LED.