the beginning & end are set... now I just need the in between

I have my ticket for Italy and my plans are starting to come together. So far I have an apartment in Venice and an apartment in Rome. Now I just have to figure out what to do for 4 days in between.

Here are my plans so far:

depart Honolulu - arrive Newark/depart Newark - arrive Milan - take the train to Venice

*7 days in Venice - apartment in Venice
*weekend with Katia & Guido (in Coccaglio)
*???? four days ????
*10 days in Rome - apartment in Rome

depart Rome/arrive Newark - stay overnight at the Newark Liberty International Airport Marriott (the hotel right in the middle of the airport!) - depart Newark/arrive Honolulu