How can I make a fan speed control switch?

[Xp]

I have a 80mm Panaflo which is quite noisy, and I wan to make a switch/rheostat to control the speed. I guess rheostat's better, right?
Do you know a How-To guide? Is it expensive to make one? I only want to use it for my case fan.

 

[chopstxxx]

rheobus------> http://www.virtual-hideout.net/guides/rheostats/index.shtml
baybus-------> http://www.virtual-hideout.net/guides/7v_12v_baybus/index.shtml

 

[Boethius]

Hi! Those articles are really cool, and they explain in detail whats going on. I have however heard that there is a possibility to buy finished kits for the fan controls. I am talking about that dual switch control
Dual LEDs

I was wondering if anyone has seen it in an online store anywhere?

 

[chopstxxx]

check pcmods.com or umax.com. They sell the dual voltage baybus for around 20 dollars i think. Those are the cheapest places I have found if you don't want to build your own.

 

[ModelM]

If your going to use rheostats, make sure you buy the ones that support the power you need. They can get quite expensive once you get around 10W.