Developer website: SoftBend
SunClock is a lightweight Dashboard widget that displays the sunlight portion of the Earth. It is based on the code from the Konfabulator widget EarthFall by Nate Barkei. Currently, you can choose between two maps, a realistic one and a Mac System 7 one.
Version 1.0.1: Now also updates upon Dashboard activation ;-)
Mac OS X 10.4 or later