'I mainly use Diptyque Do Son and Philosykos in the summer,” says Rebecca Dayan (her mini fragrance counter is pictured above). “And I travel with their solid perfumes, like Eau Duelle. I love them,” As does Tabitha Simmons, who always totes one of the glossy black compacts around with her in her bag, for the odd—and elegant—perfume refresh. Now there's an idea.