With both Emma Watson and Victoria Beckham signing on as UN Ambassadors this week, let's take a moment to discuss a) what they do and b) who else is doing it, shall we? Well, first point: UN Ambassadors are famous faces who are employed by the UN (United Nations) to bring attention to the causes they represent: from the UN Women's Fund to UNICEF, which supports disadvantaged children. And, judging by the amount of chat around VB's appointment and Emma's speech this week, the two certainly seem to be earning their keep. But before Emma and VB there was Angelina Jolie. And Katy Perry…