def would recomend a trip to Capri – just dont get lost befor the ferry leaves.
the ‘blue lagoon’ is quite a good relatively inexpensive afternoon, with a boat trip into a cave with some cool light properties.
Try to do a day trip to Pompei(sp?), but dont do a tour – take your time and make your own way around.
Personally wouldnt bother with going up Versuvious (again sp?) – its just a big hole in the ground with not much to see.
throw in some trips to the other Amalfi villages like a trip to Maiori – lovely town/village down the coast – with a good church to look around.
Other than that just do the beach and have a good time…..
Oh and enjoy the food (i hope you like sea food, pizza and mozzarella)