For Mac users, we haven't had much of a choice as far as overclocking and voltage adjustments. However, the one thing that we do have is a program called Coolbook ($10). http://www.coolbook.se/CoolBook.html I've used this since Summer 2007 on my Macbook as well as my 13" Macbook Pro. I originally bought it because my 1.83Ghz Core Duo Macbook ran at 80+C while folding. For $10, it is a steal. I hadn't fully optimized my 13" MBP's voltages until last night: Blue lines are the stock settings, green lines are the new settings! Blue lines are the old settings, green lines are the new settings for every graph except "Performance per frequency" which is Geekbench and CPUTest performance relative to frequency. Adjusted Temperature is the fan speed times the temperature. CPU Watts were read through iStat Menu, temperature was the CPU temperature diode via Temperature Monitor. Coolbook was used for adjusting voltages. CPUTest (Free, also made by the same person as Coolbook) was used to stress test. Conclusion: I give Coolbook a 5/5 rating--it's easy to use and incredibly useful! Battery life increases ~20% at max load--on my 13" MBP, this is 2:09 vs. 1:46--an extra 23 minutes of battery!