How can you make a Dual PSU setup so they share the load 50/50 - In my case 2x PCP&C-1200W?

I have read this http://www.burningissues.net/how_to/power/psu.htm but it only shows how to take the +12V from the second PSU and as far as I know, you need to put a load on all rails for a modern PSU to work optimal, so how can you connect two PSU's - Is it as simple as just to connect the two (24-pin ATX-PowerConnectores (reverse Y-splitter) or is it much more complicated? If it's more complicated than just the reverse Y-splitter, how can it be done?