[rhacy]

From my experience, deleting the power management plist on the iPhone 3G, will only stop the system from optimizing power when idle. In turn, battery run-time will be decreased without gaining any cpu clock speed increase. To actually overclock or make any change to the cpu clock speed, I think you would need to modify the read-only kernel files with a patch, and to my knowledge, that's not possible at this time.

As far as verifying cpu speed, the Checkup application by Server-Corporation, will test the cpu, memory, and nand storage read / write speeds, as well as gps and accelerometer accuracy. You could also run Mobile Terminal with the "sysctl hw.cpufrequency" command, in order to check the cpu clock speed. Although, I'm not sure if it actually tests the speed or just looks at the model number to find the speed. That said, I'd recommend testing it prior to any mods with Checkup, then reboot after any mods, and test again.

Best of luck,
R