I have always fed my dogs their daily allotment in two portions -- essentially breakfast and dinner, with a few training treats in between, or sometimes a chew of some sort. I think it's much better for their digestion, metabolism (stable insulin levels, for instance) and general comfort. You could even do three meals a day if you are reliably home with your dog during the day.
Whichever you choose, just be sure to be consistent. Dogs have an uncanny knack for knowing when it's "mealtime". My Grace is a more reliable timekeeper than Big Ben -- she finds me at 5:00 no matter where I am in the house!