We want to visit Pompei and want to leave our luggagge in Sarento for the day--is there any checking facility in the rail sation in Sorrento?

There is baggage storage at the entrance to Pompeii. AFAIK, there is no baggage storage at the Sorrento train station.

Where are you coming from?

There are no lockers at Sorrento station, although I've heard that you can leave it in the bar/cafe for a small fee and staff will watch it. This seems to be confirmed here:

http://www.sorrentotour.it/transport...ndbusinfo.html

(where you can see the bar/vafe stipulated as left luggage)

So if you take valuables with you it could be an option...

I would be surprised if the cafe at the train station stores luggage as they don't really seem to have any room. I've never noticed any signs there offering storage. Let us know if you attempt this.

The baggage storage at the entrance of Pompeii has been a free service in the past. I assume you are continuing on somewhere so if towards Naples, that might be your easiest option.

I was interested in baggage storage in Pompeii as well. How does this generally work? Is it a locked area?

Is there a general protocol for baggage storage areas around train stations or is each location different ?

The luggage storage at Pompeii is in the ticket office area at the ruins. There isn't any storage at the Pompeii train station. The info on Pompeii's website is in Italian only. Google translation:

Valet Service
Porta Marina - Square Amphitheatre
Hours:
November to March, daily from 8.30 to 17.00
April to October, daily from 8.30 am to 19.30 pm
Please leave bags, backpacks, umbrellas and other bulky items in the wardrobe
The service is free.
http://www.pompeiisites.org/Sezione....SezioneRif=674

>>>Is there a general protocol for baggage storage areas around train stations or is each location different ?<<<

Usually, just the larger stations in Italy have luggage rooms although you find a few smaller ones that will have it if there is a really popular site nearby (such as Pisa). You will probably be asked to show ID and I've seen them weigh luggage at Termini. Sometimes there will be a line when you need to retrieve your luggage so be sure to allow time if you have a train you have to catch.