[Note: We've split this discussion about homemade hash browns from this thread on the Boston board: http://chowhound.chow.com/topics/607023 - The Chowhound Team]
Verging into Home Cooking talk here, but draining doesn't get grated raw potatoes nearly as dry as squeezing the heck out of them with a ricer. You want them as moisture-free as possible, which makes it much easier to get that golden crust that you want in hash browns. (They also discolor sitting in a strainer: you want them in the pan fast.) Doing good hash browns for my Sunday breakfast has been one of my cooking Grails for years now. I'm almost satisfied with my results.