fan controllers

do any of you guys use fan controllers? do they help at all with keeping a reasonable balance between fan speed and noise level? or is it just one of those novelty things that you buy just to mess around with?

I have fan controllers for two case fans, the fans on the power supply, and the cpu fan. They are not integrated on one main controller though, they all have separate controls.
They are nice to have. I always leave the cpu fan on high (its a zalman, so its quiet anyway), but the case and power supply fans vary depending on ambient temp and use. I keep my computer in my room, so I like to be able to turn down the fans at night when I sleep. Its a nice feature to have.

I use individual controllers too. I have one on my exhaust fan and one on my CPU fan. I dont use a controller on my intake fan cause it would just read ambient air temps.