Would you fancy cycling on a steel wire above the traffic? That was Martin Angelov's idea, Kolelina, which he presented to the TEDx conference in Sofia. The Kolelina site is dedicated to being a 'lab for alternative transportation, crazy ideas and bicycle lifestyle' which is an understatement. The concept involves cyclists riding on a grooved track with a harness attaching them to the guide wire to keep you locked in. Touted as an option for navigating busy junctions it could be an exciting way to spice up your cycle to work in the morning.