Erik Wachtmeister

Erik Wachtmeister

Tony Barson/WireImage

The BestofAllWorlds site, which starts Aug. 27, will allow users to mingle online with like-minded people, find restaurants and nightlife in city guides and discover who’s attending events such as Art Basel in Miami and England’s Royal Ascot horse racing, said Erik Wachtmeister, whose father was a Swedish ambassador to the U.S.