Docking status information is available in XML for the London bike hire scheme ("Boris bikes").
Each point represents a docking station. You can see how the shape of this cloud sits over London on this Google map. Blue means empty docking station. Red means full docking station. Light blue and light red mean almost empty and almost full, respectively.
Not so much on Saturday and Sunday, but clearly (to me) on Monday you can see a 9am rush hour move of bikes into the centre, and a 5pm move of bikes back out to the edges again.