Walk under a high voltage power line with one, on a dark night (take a torch so you can see what you walking into ).
Which reminds me, if we are getting light energy from the tube when walking into a magnetic field (ocelating- (i cant spell)) where does the energy come from to power this flourecent light? Are you some how sapping the wires of voltage, and if (say) the wires had 0 resistance, some energy must be lost somewhere to allow for people wandering under power lines with light bulbs.