Walk around the Piazza Navona at dusk/after sunset - look for the ‘finger dancer’ who uses his fingers as puppets on a little table stage he sets up. And drop in on all the little groups on the piazza, some singing, some playing instruments, etc. Get a gelato or tartufo dessert at nearby (see link). The tartufo is a signature dessert - often you will see people eating it while sitting near a fountain or strolling the piazza.
Enjoy!
goitaly.about.com/od/romeitaly/ss/piazzanavona_5.htm
Here is a site with ideas that might help:
romanlife-romeitaly.com/things-to-do-in-rome-italy.html
And I found this interesting:
en.wikipedia.org/wiki/Santa_Croce_in_Gerusalemme
We had a guide (an Italian at that church helped us around) and he took us back to the right and down some stairs (to the Chapel of St. Helena maybe?) and there we saw the foundation of St. Helen’s house/palace (she was mother of St. Constantine - this church is built around/over her home). Very cool. Now I tell people I visited St. Helen’s house whenever they mention Constantine!!