Naples used to be on the black list for women travelers, but conditions have improved enormously after years of refurbishment in the city's historical district. Southern Italians are also much more accustomed to seeing blond visitors.
However, women chronically attract men's attention and often have to fend off their proffered "friendship." Most often, ignoring remarks, avoiding eye contact, and proceeding on your way as if you hadn't noticed anything is the best approach.
Always dress appropriately. Especially in summer, remember that Italian women are attired more conservatively in urban surroundings than their counterparts in the United States: Reserve your strappy tanks and short shorts for the beach, ladies.
Should you ever perceive a real threat, immediately request assistance from a policeman, a storekeeper, or even a passerby (elderly women are usually perceived as particularly forbidding by young Italian males). In general, avoid seedy neighborhoods where you don't see many women strolling around, and use your common sense. Also women should not walk around alone in sketchy neighborhoods after dark.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.