Another really useful Dashboard widget is Deep Sleep, which allows you to easily send your Mac into a power saving hibernation. Ed Hunsinger has the best explanation of Mac sleep modes that I’ve seen so far.
The nice thing about Deep Sleep is that it can supplement your default suspend activity for when a Mac laptop lid is closed. You can have the close go to the basic “sleep” mode and clicking on the widget lead to a “hibernate”. Very handy.
And the Deep Sleep widget is free to boot.