Hi, I've been looking for these myself. I was there last fall and saw scores of guided tours mostly comprised of 30 or so people being sheparded around with a flag holder who usually mentioned something about Russell Crowe.
But I also happened to witness a terrific one, a very knowledgable sounding academic with a very small group of 6 people. I've been scouring the web and first I found a tour operator that seemed great - who gave private tours - but at a high cost of $50/hr. I emailed with her alot and found her to be most promising, but the cost was just too much for me. But here's her website:
http://www.rome-tours.com/index.shtml
Then I found a very promising website:
http://www.scalareale.org/
But the problem is with them that they only offer certain tours depending whose signed up and so at 2 weeks from my departure I still don't have an itinerary to my liking. (The tours offered or at bad times for me, etc). The other downside with them is that the email exchange has been very frustrating - with long delays in replies. But their site really did look great and it offers lots of interesting info, so check it out atleast.
What I'll probably end up doing is just asking the concierge at my hotel for suggestions of a tour. There are tons offered, it's just a matter of finding a good one of course. Do you have hotel reservations yet? Because you could contact the concierge and perhaps get something lined up.
I also found this:
http://www.insidersitaly.com/
But it was way out my budget.
And here's the link to the Offical Rome Tourism site:
http://www.romaturismo.com/
And here's another informational site:
http://www.enjoyrome.com/main.html
And lastly, I found this yesterday and it's a hoot - it's like FT for Ancient Roman nuts and actually just wanted to share it with someone anyway...
http://web.archive.org/web/20001204231400/www.ancientsites.com/xi/places/home /index.rage?loc=Rome
I have tons of more bookmarks but I should stop now!
If I find a tour when I'm there, I'll post it here.
I hope you have a great trip - I can't wait to go!
[This message has been edited by sk3 (edited 05-08-2003).]