Wat? I'm with St John Ambulance, that's why I was asking. I've done a couple of duties myself in the past month, and just the way you said 'on duty' rang a bell for me o_O
Small world. Does that make you a cadet then? Did you do anything for the Olympics? Still got my shiny accreditation pass. Told it could fetch about a hundred quid on eBay. :)