Remove clothes. Begin urinating whilst dancing to Born this Way by Lady Gaga (music in your head). At completion of flow, see which number the splatters on the floor most resemble.
What about people who spin in circles and think everything looks like a 0? It isn't completely random if someone is biased towards a number, especially when the picture is uncertain. A possibly better approach would be to count the number of 'splatters' (or whatever), and mod by some smaller number (i.e., 16).
