I will be traveling to Italy soon, and I will be taking a small camera backpack. I will be visiting Sorrento, Pompeii, Rome and Florence. I have heard that some of the museums will not allow visitors to enter with backpacks. At those places that don't allow backpacks (and I am still not sure which museums and sites these are), are there secure lockers or storage areas for your belongings? Thanks for the help.
The ones I remember were always staffed and you received a ticket for your bag but stored in an open area behind a counter.
Often those places will require holding a form of ID from you before you can check a bag (or get an audioguide). If you have an expired driver's license, take it with you and use that. Do NOT give them your passport.
The major places have a storage area that has very limited access, usually a room behind the desk where you check your bag and get a ticket for it. I've never been asked for ID to check or retrieve my bag, so make sure you don't lose the ticket. A couple of places (the Borghese Gallery, for example) will let you take some belongings with you in a clear plastic bag, but not cameras. I don't usually carry a purse, just a small daypack, but I was able to take my wallet, meds, a bottle of water, and other documents with me into the museum with the bag. Smallish purses are fine.