The Island in the Tiber (Isola Tiberina)
http://www.isolatiberina.it/Index_e.html has a great restaurant right next
to the bar on the left as you pass across on the Ponte Fabrico (sp) (the one
with the ancient heads on pedestals). The island is easily one of the most
atmospheric and evovative places in the entire city, and I never miss an
opportunity when there to visit it. Also, make sure you see the Bocca della
Verita (Mouth of Truth) in the portico of a 7th century early Christian
Church not far from the Circus Maximus (I forget the name).
http://www.freereservation.com/roma2/22.htm.
http://www.dpsusa.com/bocca_verita_history.shtml
http://en.wikipedia.org/wiki/Bocca_della_Verit%C3%A0 It's definitely worth a
look; a fun and legit tourist attraction going back centuries..

Have a great trip.

Brian