Forget the theater, cinema or ballet – debating is where you’ll find the smart set these days. Spearheading the trend is a new leader in global intellectual stimulation, Intelligence Squared, and at its head is the formidable – and very chic – Yana Peel. It was founded in the UK in 2002 with a simple idea: a traditional debate, with two speakers per side (high-caliber names have included Tony Blair and Patti Smith) arguing passionately over subjects such as terrorism, pornography,