a simpler way of making nodes move dynamicaly than karma based momentum (also possibly more useful?)
whenever a nodelink is traversed, the distance between the 2 nodes that it connects is shortened, unfortunately this means firing a server request evrey time a link is clicked,
perhaps data can be stored locally (cookies) and then sent every x seconds.
other nodelink popularity measures,
as nodes shorten, they also fatten so main highways between important nodes start to emerge – this, like node_gravity has to have an upper limit to stop black holes forming.
