Anyone who has played with the wax dripping from a candle burning atop a wine bottle will know how incredibly satisfying it can be. I've completely lost track of conversations in pubs and cafés where candle wax is available for the peeling, melting and construction of miniature skyscrapers. The distraction has proved so difficult to resist that, on one occasion, the person I was with snatched the wax encrusted bottle away and plonked it on a neighbouring table.