I took the Rick Steves' 14 day Best of Europe tour back in October '06, and the trip's biggest disappointment (to me) was that "Francesca" was not available to guide our group through the ancient Roman sites. The guide we were assigned was adequate, but hard to understand and a bit (sorry) boring. For our next trip to Rome, would it be possible to find Francesca and arrange for a private tour? Just about everyone who goes on a ETBD tour in Rome says she is amazing.
We used one of ETBD's reccomended guides in Florence and I have found that if you call ahead once you have any idea when you'll be in a particular city, you can usually get them to do a tour for you. Do be aware that this is not cheap but very worth it if you're willing to spend the money.
Terri, Francesca is in the RS Italy book (and I would assume the Rome book). She's listed under the Guides section. Sorry, I don't have my book with me at the moment, but if you look, you will find her website and e-mail info. She is very expensive but worth every single Euro. We had her as a guide on our RS tour (Venice, Florence, Rome) and she was the BEST guide we had! However, having said that, our friends who weren't on the VFR trip (but were in Rome at the same time) had booked Francesca for their own private tour and she cancelled at the last minute to take our tour group around. She had another staff person fill in for her, but, still, it wasn't the same great tour for our friends. Let me know if you can't find her in the books and I'll track down her contact info.