I still find the ticking of a pomodoro timer to be the best way to make me start cranking out work. There's just something about tik tik tik tik that springs me into action.
I've just discovered Pomodoro (on Day 5) and I have to say it's completely revolutionised my productivity. I've gone from 3 or 4 hours of unfocused time a day, to 12 hours of laser like focus on stuff that matters.