Studies are showing that both men and women in their 30s, 40s and 50s, in large numbers, are taking gender-based vacations. Hotels are seeing the trend and creating specific packages focused on activities such as golf or spa treatments. "For men, the annual guys' trip is male bonding at its best," one industry insider says. "There's usually some competition, lots of cocktails and a healthy dose of camaraderie. These trips are anchors that hold men's relationships together in a sea of busy personal and professional lives."