jkzahn - don't know if you already found this on the site I linked above (the Romaturismo.com site) but there is a "Rome Key Card" available:

As from June 1st, a prepaid card to visit the city at the cost of €18
The Rome Key Card includes:

- 6 journeys lasting up to 75 minutes valid for all of Rome's public transportation

- 1 city tour by bus with a/c and multilingual guide (English, French, German, Spanish and Japanese)

- 1 entrance to the Capitoline Museums and reductions in other City Museums

- discounts in more then 100 shops, movie theatres, theatres, bookshops, restaurants, car and scooter rentals, etc.

- a city map, a public transport (Atac) map, brochures on the events and a guide to the services that participate in the convention

I found this under "events".

And just surfing around, there's an all night extravaganza planned for tomorrow (9/27). Looks great - I'm bummed to have missed it! This is from the site:

White Night!
09.27.2003

Excitement grows for the first Roman Nuit Blanche: from 8pm to 8am, the Eternal City will be animated by events involving visual arts, music dance and theatre, meetings, volunteer work and shops and eateries will stay open all night. The initiative is free and will also take place in Paris and Brussels, focusing on simultaneousness, multiculturalism and solidarity, in a climate of festiveness and curiosity for different cultures, as part of the twinning of Paris and London, and to stress the connection between the two capitals and Brussels. An extraordinary event, unheard of before in Italy, that will involve the entire city, from the center to the suburbs, while concentrating along privileged itineraries and include the major museums and cultural organizations, both public and private, along with sports centers and metro and train stations.

Over 100 events all over the city, arranged along 8 itineraries:

1. Center/Trastevere
2. Cinecittą
3. Ostiense/Testaccio
4. Villa Borghese/Parioli
5. Ponte Milvio/Roma Nord
6. Eur/Garbatella/ Ostia
7. Tiber River
8. Paris and Rome: special events in the main venues of the Rome of French imagination

22 film theatres and 28 theatres will have long hours, 24 museums, 51 art galleries and 9 culture institutes will stay open all night. Open museums, including the Borghese Gallery, the Capitoline Museums, the Complex of the Victor Emmanuel Monument, the Colosseum, the Papal Stables at the Quirinal, Villa Medici, the Napoleonic Museum, the MACRO, Palazzo Braschi and Palazzo Farnese, will be free and will also offer music, readings and installations.

Public transportation will be free starting from 10pm, bus services will be increased throughout the night, and the metro will stay open too. Navigation on the Tiber will be functioning also.

Among the many scheduled initiatives, we would like to point out the inauguration of the Globe Theatre of Villa Borghese, where it will be possible to watch the rehearsals of Romeo and Juliet directed by Gigi Proietti, and two concerts at dawn on the terrace of the Pincio (jazz with Rea, Gatto, De Vito, Mirabassi, Pietropaoli, Petrella, Moroni, Sferra) and at the Janiculum (music by Rossini, Mascagni, Bellini, Verdi, performed by the Orchestra of Rome and Lazio)

In Piazza del Campidoglio Nicola Piovani and Vincenzo Mollica will host a meeting on Fellini and music, followed by a concert of the Orchestra Aracoeli directed by Piovani himself. Theatre performances will be held at Trajan's Markets, the Auditorium of Mecenate, Largo Argentina, Palazzo Altemps (with Albertazzi), the Sant'Angelo and Sixtus bridges, and the Teatro India (with Marco Baliani).

Also, guided tours of the basilicas of San Clemente, SS. Giovanni e Paolo al Celio, SS. Cosma e Damiano, the Roman Houses at the Celio, the Domus Aurea, the Spada Gallery, the Academy of Fine Arts, the Pyramid of Cestius, the set of Gangs of New York at Cinecittą.

In the suburbs, in Largo Zappalą and the Anagnina Station, a workshop of graffiti by Roman and non Roman writers and hip hop and electronic music.

Literature events include readings in libraries all over the city: the Rispoli (Forbidden Readings), Orologio, Ostiense, Flaminia, (Readings in the Dark), Villa Leopardi, Morante (Ostia), the Casa delle Letterature (Mystic and Wisdom Readings), piazza Mattei. Tastings of local products at Castel Sant'Angelo, Via del Corso, etc., as well as sports events in various venues.

The White Night will also be a night of solidarity with the homeless. Some parishes and city shelters will offer dinner, and fund collecting will be arranged in every venue involved in this great event.