Mate,
I got the inspiration from here and hooked up a few myself, here's how I did it:
I got the parts from the local rubbish tip - pulled three fans out of old computers (new ones will cost around $25), and also two old mobile phone chargers (I found two that had two diticnt wires, 1 x all black, and 1 x black and white)
My computer fans all had three coulr wires: Fan 1 had a blue, red, and black, Fan 2 had a yellow, red, and black; Fan 3 had a Blue, green and black.
While I was at the tip I got a few other thing for the grow box as well - relfectors, small chain, a small fan motor, lap top cooling pad etc etc.
Now
with the charger - the output from these things is very small so I didn't think it was going to kill me so I cut the off the ends which connect ot a phone, and while keeping the two ends apart I plugged it in and turned it on. Then just like you do with the car battery charger jumper leads - I quickly touched the two ends together to make sure that the actual charger was working. Both mine worked.
Next I cut off the ends of the fan wires and stripped/exposed the actual wires inside, now it's just a simple matter off connecting/touching the chargers black and white with fans black wire. And then touch the chargers all black wire with any of the other wires until the fan starts working.
I found that two of the fans were good so these became my exhaust fans, I then used the old lap top cooling pad (which had three small fans) as the air intake. I'll post some pics tomorrow.