Sleep Monitor monitors and profiles your Mac's energy use, and can help you identify power management problems.
With Sleep Monitor you can easily build an energy profile spanning days, weeks, and months. Your profile will contain a record of all the power events, battery changes, and energy state information.
ANONYMOUS Since installing on my Powerbook (12" 1.5G) the Powerbook takes what seems to be an eternity to go to sleep when the lid is closed - Takes about 60 seconds instead of the normal instant sleep. Removed Sleep monitor and everything back to normal.