The founder of Autodesk John Walker has always been into Astronomy. I found the latest web site of Johns which shows the current Earth or Moons view completely configurable to show where it is day or night.
Main Earth & Moon Viewer Page
http://www.fourmilab.ch/earthview/vplanet.html
Current Earth View
http://www.fourmilab.ch/cgi-bin/uncgi/Earth/action?opt=-p
Cheers,
-Shaan
