Rome: English speaking church service

I think this is pretty comprehensive http://www.initaly.com/travel/info/church.htm. I don't think any are in Trastevere, but bus service is excellent, even on Sunday.

Santa Susanna is the home of the American parish in Rome. If you are looking for a vibrant community with a taste of home (and obviously English speaking), you might want to check it out.

Masses in St. Peter's are held throughout the day in a variety of languages. If you are just looking for an English mass, this would do it but if you want a community take the suggestion above. Masstimes.org can also be used to find masses throughout the US and some parts of the world. Very handy when in a strange city for just a weekend.

I was in Prague recently and was surprised to see that they had several churches with regularly-scheduled English Masses. Here in Rome, on the other hand, where you have millions of Americans, Brits, Aussies, and other English-speaking people walking around all the time, there are very few regularly-scheduled Masses in English. It's unfortunate, but there are some options that do exist: Santa Susanna (http://www.santasusanna.org American national Church)
St. Patrick's (http://www.stpatricksrome.com/services.asp - but I am not sure if their web site is up-to-date so you might want to contact them to verify) San Silvestro in Capite (http://sansilvestroincapite.com/mass_times.html English national Church) I would warmly encourage you to consider attending Mass in Italian or in one of the other languages offered, for a more "universal" experience. Even though you might not know the responses, you will know exactly what is going on.

If you go to St Peter's first thing in the morning (ie, get in line before it opens), there are typically a number of priests waiting. Once the basilica opens, they disappear into the sacristy and go to say Mass at the various side altars. If you want an English-speaking Mass close to Trastervere, this is probably the easiest way to find one (although I find my attention/focus is heightened when I don't know the language and therefore need to follow very closely).

Sherry makes a good point: between 7am and 8:30am priests can go there to celebrate privately. You should be able to find one who is celebrating in English.

In Rome this past week, walked by St.. Andrew's on Quirinale hill, a small Scottish congregation in a non-church building, with sign on fence outside inviting public to Sunday morning service at 11:00.
Link:http://en.wikipedia.org/wiki/St_Andrew%27s_Church,_Rome

Thank you for all of your suggestions! Bryan, thank you for suggesting an Italian service too. I was in Sienna a couple of years ago, and came upon a Church while the Priests were doing their evening vespers; I forgot about what a wonderful experience that was :) Thank you!!!!