Will be in Rome for 11-12 days

There are 1-week, 3-day and 1-day transit passes available. When I was in Rome this May, cost was 16 euro, 11 euro and 4 euro respectively. The 3-day and 1-day passes can be purchased from a ticket machine, but don't recall whether the 1-week pass is available from the machine or must be purchased at a ticket window. Remember that Rome transit passes expire at midnight on the last day of validity, so you loose almost a full day if you validate a pass in the evening.

excellent. i figured there must be. i'll definitely keep the validation issue in mind.

I think once you get there you'll find that you won't use public transport and much as you might think. The city is small and very walkable. I hardly ever use public transport when I'm there. The metro won't get you close to most sites and depending on the time of day the buses can be slower than walking. Donna

interesting. we'll be staying near termini, so it is a good distance away from the other stuff... plus it will be around Christmas, and i'm anticipating the weather not being super pleasant. i guess we'll do the roma pass and then decide if we want to get a transit pass as well after that.

You realize that the Roma Pass includes public transportation, right? Per their site: 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.

i do, however, IIRC, it's only good for 3 days or so. i don't think i'll want to buy 4 Roma passes for my stay.

I used only the metro when I was there. While it doesn't get you RIGHT to most things you would want to see it usually is pretty close. Within a few minutes walk to alot. Termini is a good area since the two lines intersect there.

The Roma pass does include transit but only lasts 3 days. Start with that and see how much you use it. As someone already said, the Metro only goes near a few sights, all others are long walks from Termini area or by bus. I prefer the walks as most do but if you can't walk as much you may need the buses more. Transit is pretty cheap in Rome so the pass probably only makes sense if you are taking a lot of buses.