Mobile orienteering

This is a competition for pairs: one person (the "runner") has a mobile phone and the electronic timer (SI card, dibber, magic finger, whatever you like to call it) and visits the control points; the other person (the "control freak") has a mobile phone and the map with the course marked but stays at base and instructs the runner where to go! The runner visits the control points in order as per a normal orienteering course. Pairs may then swap over. If you are not in a pair, don't worry - just turn up and we'll find you a partner.