Also, for people who have a tough time getting up in the morning when it's cold and dark, this makes a huge difference:
http://www.biobrite.com/products.php...nRise%20Clocks
Can set it so it starts brightening anywhere from 15min-1.5hours before you get up. When the alarm finally goes off, you can immediately open your eyes to the light. Makes it 100x easier to get up in the morning. No squinting or anything.