A Thai barman may have hit the jackpot when he picked up a strange lump of yellow wax which could prove to whale vomit worth up to US$500,000. Boonyos Tala-upara found the 10kg (22lbs) blob while walking along a beach on the island of Koh Samui in southern Thailand. A friend told him it looked like highly valuable ambergris, a secretion from the intestines of sperm whales which can be used to make luxury perfume. The lump was soft when Boonyos poked it, and with a texture unlike a candle. It…