While many are still trying to get used to the 20% tip for food servers, waiters and waitresses in New York are now suggesting diners leave tips of up to 30%! Michael Lynn, a professor of consumer behavior at Cornell University reported in a recent paper that the first signs of a shift in New York's tipping culture was when 20% went from being a generous amount, to being the norm. From a study of around 9,000 credit card receipts from a restaurant in Poughkeepsie he found that 37% of customers left tips of more than 20%. For what it's worth, Tripadvisor.com recommends that waiters and waitresses should be given a bonus of up to 20% for good service, while bartenders should be left $1 for every alcoholic drink purchased. (New York Post)