Maybe attach a 12V halogen incandescant light bulb to it? That should qualify as a load... 😀

For a one shot test, you can take a pail of water with your leads inside and calibrate it by using any electrolyte (salt, H2SO4, etc). You're going to want about one ohm of impedance (no need to run at full blast).
https://en.wikipedia.org/wiki/Liquid_rheostat

I remember reading somewhere about dedicated PSU testing machines. Does anyone know about these?

Errius wrote:

I remember reading somewhere about dedicated PSU testing machines. Does anyone know about these?

they are stupidly expensive

Thousands. Plus, how are you at reading traditional Chinese?
http://www.sunmoontec.com/cpzs.asp?MidCode=SM … %BA%D4%D8%BB%FA

I use a combination of 4R7 7W ceramic resistors (each one draws roughly 1A @ 5V) and 50W 12V halogen lamps for load testing computer power supplies.

I just connect a failed-but-still-spinning hard disk

Ok so if I connect three good working hard drives, the power supply has 3 molex and 2 floppy, and nothing to the main 12 pin plug would that be enough for a load test? Also the fan does not work so how long could I play around with it without a fan sucking hot air out or can I take the cover off and hope it doesnt get hot?

Three working hard drives should only be good for <<100 watts. Also, if the fan is seized it should be pulled. You can temp in another fan, either external or internal, to guarantee airflow into the PSU.

If 3 hard drives only use about 100 watts how much wattage do I need to use before the 200 watt power supply is in a load state?

I would be amazed if they use 100W. 15k RPM drives, for instance, use between 15 and 20W.
http://ixbtlabs.com/articles2/storage/hddpower-pro.html