Roma Pass, Rome
I think you have to weigh the Pros and Cons of buying a Roma Pass. For EU$25 (in 2011), you gain free entry to the first two museums and/or archaeological sites, then discounted entry to all other museums and/or archaeological sites, free use of the city's public transportation network, discounted tickets to exhibitions or events, a map and few other items. It's valid for three days from their validation date.
We didn't end up buying the Roma Pass. And, I don't think it cost us too much more by not buying it. Their are many places you can visit for free. Look at your itinerary, the cost of just the transportation ticket (various prices for different time frames) and see if the cost makes sense to you.
If you want to avoid lines and are planning to see quite a few archeological sites in Rome within a week, the Archaeologia Card is a good buy.
It includes these sites:
Colosseo, Palatino and Palatino museum, National Roman Museum (Palazzo Altemps, Palazzo Massimo, Crypta Balbi, Terme Diocleziano), Terme di Caracalla, Cecilia Metella, Villa Dei Quintili.
The card costs € 23,50 for all 9 sites, valid for a week, and you can buy it at the National Museum near Roma Termini (probably at other locations too).
More info and addresses here
Note: Discount for EU citizens between 18-25 yrs and teachers: € 13,50.
EU citizens under 18 and over 65 the card is free.
Fondest memory: Combine this card with the CIS transportation card, also valid for 7 days (€ 16) and you are all set to discover Rome.
(link checked for 2011, still good)
If you are going to be staying in Rome for 3 days or more and you plan to go to a lot of sites, I recommend the Roma Pass. It gives you free entrance to your first 3 sites and then a reduced rate to the rest of the sites you visit in 3 days. I downloaded a list of all of the sites and discounts from the Roma Pass website. It was very helpful in deciding which places to go to but some of the prices are inaccurate because in Rome if a museum has a special exhibit, they charge you more for the entrance. So you have to know how much every site's entrance is on the days you are there to work out how to get the best deal. You want to make sure you visit the most expensive sites for your first 2 sites to get the most for your money. The Roma Pass also lets you use transportation for free for those 3 days. Please note that the Roma Pass cannot be used at all sites. Don't waste your money at any of the free sites on those 3 days.
Fondest memory: Some things I recommend using the Roma Pass for: Colosseum/Forum/Palatine Hill, Capitoline Museums, Ostia Antica (and transportation to Ostia), Borghese Gallery, National Museums of Rome.
If you are planning to visit Rome buy a Roma Pass Card website: www.romapass.it. (EUR 25)It is a special tourist cultural card that enables both tourists and interested local residents, the opportunity to benifit from various discounts and services that makes it easier to enjoy the splendour of Rome.
Free entry to the first 2 visited museums and / or archaeological sites of your choice
Reduced ticket prices to all other museums and / or archaeological sites visited thereafter
Free use of the city's public transport network (urban buses and trains, Underground lines A and B, Met.Ro trains: Roma - Lido, Roma - Viterbo for the Roma - Sacrofano section, Roma - Pantano railways lines within the urban territory of the City of Rome) Trenitalia trains and Cotral buses are not included.
Discounted tickets to exhibitions, events and other collaborating operators and businesses.
Reduced charges for use of the On-call Multi-lingual Medical Service for Tourists (MET Travel Health)
Tourist cultural service Roma Informa.
At the Colosseum a reserved turnstile is available for Roma Pass holders to get direct access to the monument