I installed it on my 10.6.6 iMac after failing to get smcFanControl to run. It shows up in the System Profile rather than as a separate file, which might be what's causing some people problems.

However, now my heat issues are WORSE. For low-demand stuff, it does help (i.e. something that might put me at 120F before stops around 110F), but high demand enters a feedback loop that takes the fan up to max and the temperature just keeps rising. I have to wonder if this is of a piece with how 10.6.x has broken heat control overall. Even setting the base speed to the maximum allowed 3500 rpm doesn't stop the runaway from happening. It's as if the OS knows something is trying to stop heat buildup and is determined to make MORE heat to counter it.