Unplugged

Most days I come home from work and can't wait to start writing again. I'll plant myself in front of my laptop, crank up my iTunes, and before I know it its time for me to hit hit the sack. Yesterday was not one of those days.Maybe it was the Chardonnay I drank at happy hour*, maybe it was the miserable case of insomnia I suffered the previous night, or maybe it was because I'd already spent nine hours in front of a computer cranking out web copy for work. Whatever it was, I wasn't feeling it.So I turned off my computer and gave myself the evening off (aside from a few teeny tiny revisions I had to make). I justified it to myself because I'd just turned in an outline for a new project the previous night and these restless, uninspired feelings are so rare and all I wanted to do was lie in bed and read. Today I woke up refreshed and ready to write! What do you do when you're running low on motivation?
*Is it really ever just an hour?